content: <PAGE>   1
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 8, 1997
                                                  Registration No. 333-__________
  ===============================================================================
  
  
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                                 -----------------
                                      FORM S-8
                               REGISTRATION STATEMENT
                                       UNDER
                             THE SECURITIES ACT OF 1933
  
                                 -----------------
                         PIONEER NATURAL RESOURCES COMPANY
               (Exact name of registrant as specified in its charter)
  
               DELAWARE                                       75-2702753        
      (State or other jurisdiction of                       (I.R.S. Employer     
       incorporation or organization)                      Identification No.)    
                                                    
  
                             1400 WILLIAMS SQUARE WEST
                           5205 NORTH O'CONNOR BOULEVARD
                                IRVING, TEXAS 75039
            (Address of principal executive offices, including zip code)
  
                                 -----------------
  
                  PIONEER NATURAL RESOURCES COMPANY STOCK OPTIONS
  
            PARKER & PARSLEY PETROLEUM COMPANY LONG-TERM INCENTIVE PLAN
  
                              (Full title of the plan)
  
                                  MARK L. WITHROW
                             1400 WILLIAMS SQUARE WEST
                           5205 NORTH O'CONNOR BOULEVARD
                                IRVING, TEXAS 75039
                                   (972) 444-9001
             (Name, address and telephone number of agent for service)
  
                                      copy to:
                                 ROBERT L. KIMBALL
                               VINSON & ELKINS L.L.P.
                             3700 TRAMMELL CROW CENTER
                                  2001 ROSS AVENUE
                              DALLAS, TEXAS 75201-2975
                                   (214) 220-7700
  
  
                          CALCULATION OF REGISTRATION FEE
  <TABLE>
  <CAPTION>
  =======================================================================================================================
                                                                                        Proposed
          Title of securities            Amount to be         Proposed maximum     maximum aggregate        Amount of
           to be registered               registered       offering price per unit* offering price*     registration fee
  - -----------------------------------------------------------------------------------------------------------------------
  <S>                                  <C>                         <C>                <C>                    <C>    
  Common Stock, $0.01 par
  value per share...................   1,328,061 shares            $39.62             $52,617,777            $15,945
  - -----------------------------------------------------------------------------------------------------------------------
  </TABLE>
  
  *  Estimated solely for purposes of calculating the registration fee in
     accordance with Rule 457(h) under the Securities Act of 1933 and based on
     the average of the high and low prices of the Common Stock reported on The
     New York Stock Exchange on August 29, 1997.
  
  
  ===============================================================================
  
  <PAGE>   2
  
                                  EXPLANATORY NOTE
  
           On August 7, 1997, MESA Inc., a Texas corporation ("Mesa"), merged
  with and into the Registrant (the "Merger") pursuant to an Amended and Restated
  Agreement and Plan of Merger (the "Merger Agreement") dated as of April 6,
  1997, by and among the Registrant, Mesa, MESA Operating Co., a Delaware
  corporation and a direct wholly-owned subsidiary of Mesa, and Parker & Parsley
  Petroleum Company, a Delaware corporation ("Parker & Parsley"). Pursuant to the
  terms of the Merger Agreement, (a) the Registrant assumed each outstanding
  option to purchase common stock, par value $.01 per share, of Parker & Parsley
  ("Parker & Parsley Common Stock") granted under the Parker & Parsley Petroleum
  Company Long-Term Incentive Plan (the "Plan"), and (b) the assumed options
  became exercisable for common stock, par value $.01 per share, of the
  Registrant ("Pioneer Common Stock") at the rate of one share of Pioneer Common
  Stock for each share of Parker & Parsley Common Stock. The Registrant is
  filling this Registration Statement on Form S-8 to reflect the assumption by
  the Registrant of each such option to purchase Parker & Parsley Common Stock
  and the conversion of the options for Parker & Parsley Common Stock into options
  for Pioneer Common Stock in the Merger.
  
                                      PART II
                 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.
  
           The following documents have been filed with the Securities and
  Exchange Commission by Pioneer Natural Resources Company, a Delaware
  corporation (the "Company"), and are incorporated herein by reference and made
  a part hereof:
  
           (a)  The Company's Registration Statement on Form S-4 (File No.
                333-26951) dated June 27, 1997; 
  
           (b)  The Company's Current Report on Form 8-K dated August 7, 1997;
                and
  
           (c)  The description of the Company's Common Stock, $0.01 par value
                per share, contained in Item 1 of the Company's Registration
                Statement on Form 8-A filed with the Commission pursuant to the
                Securities Exchange Act of 1934 (the "Exchange Act") on August
                8, 1997.
  
           All documents subsequently filed by the Company pursuant to Sections
  13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a
  post-effective amendment that indicates that all securities offered have been
  sold or that deregisters all securities then remaining unsold shall also be
  deemed to be incorporated by reference herein and to be a part hereof from the
  dates of filing of such documents. Any statement contained in a document
  incorporated or deemed to be incorporated by reference herein shall be deemed
  to be modified or superseded for purposes of this Registration Statement to the
  extent that a statement contained herein or in any other subsequently filed
  document which also is or is deemed to be incorporated by reference herein
  modifies or supersedes such statement. Any statement so modified or superseded
  shall not be deemed, except as so modified or superseded, to constitute a part
  of this Registration Statement. Upon the written or oral request of any person
  to whom a copy of this Registration Statement has been delivered, the Company
  will provide without charge to such person a copy of any and all documents
  (excluding exhibits thereto unless such exhibits are specifically incorporated
  by reference into such documents) that have been incorporated by reference into
  this Registration Statement but not delivered herewith. Requests for such
  documents should be addressed to Pioneer Natural Resources Company, 1400
  Williams Square West, 5205 North O'Connor Boulevard, Irving, Texas 75039,
  Attention: Secretary, (972) 444-9001.
  
  ITEM 4.  DESCRIPTION OF SECURITIES.
  
           Not applicable.
  
  
  ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.
  
           Not applicable.
  
  
  
  
                                        -2-
  <PAGE>   3
  
  
  ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  
           Article Twelfth of the Restated Certificate of Incorporation of the
  Company provides that the Company shall indemnify its officers and directors to
  the maximum extent allowed by Delaware General Corporation Law. Pursuant to
  Section 145 of the Delaware General Corporation Law, the Company generally has
  the power to indemnify its present and former directors and officers against
  expenses and liabilities incurred by them in connection with any suit to which
  they are, or are threatened to be made, a party by reason of their serving in
  those positions so long as they acted in good faith and in a manner they
  reasonably believed to be in, or not opposed to, the best interests of the
  Company, and with respect to any criminal action, so long as they had no
  reasonable cause to believe their conduct was unlawful.
  
           With respect to suits by or in the right of the Company, however,
  indemnification is generally limited to attorney's fees and other expenses and
  is not available if the person is adjudged to be liable to the Company, unless
  the court determines that indemnification is appropriate. The statute expressly
  provides that the power to indemnify authorized thereby is not exclusive of any
  rights granted under any bylaw, agreement, vote of stockholders or
  disinterested directors, or otherwise. The Company also has the power to
  purchase and maintain insurance for its directors and officers. Additionally,
  Article Twelfth of the Restated Certificate of Incorporation provides that, in
  the event that an officer or director files suit against the Company seeking
  indemnification of liabilities or expenses incurred, the burden will be on the
  Company to prove that the indemnification would not be permitted under the
  Delaware General Corporation Law.
  
           The preceding discussion of the Company's Restated Certificate of
  Incorporation and Section 145 of the Delaware General Corporation Law is not
  intended to be exhaustive and is qualified in its entirety by the Company's
  Restated Certificate of Incorporation and Section 145 of the Delaware General
  Corporation Law.
  
           The Company has entered into indemnity agreements with its directors
  and officers. Pursuant to such agreements, the Company will, to the extent
  permitted by applicable law, indemnify such persons against all expenses,
  judgments, fines and penalties incurred in connection with the defense or
  settlement of any actions brought against them by reason of the fact that they
  were directors or officers of the Company or assumed certain responsibilities
  at the direction of the Company.
  
  ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.
  
           Not applicable.
  
  ITEM 8.  EXHIBITS.
  
           Unless otherwise indicated below as being incorporated by reference to
  another filing of the Company with the Commission, each of the following
  exhibits is filed herewith:
  
           4.1   --   Parker & Parsley Petroleum Company Long-Term Incentive Plan
                      (filed as Exhibit No. 4.1 to Parker & Parsley's
                      Registration Statement on Form S-8, File No. 33- 38971 and
                      incorporated herein by reference).
  
           5.1   --   Opinion of Vinson & Elkins L.L.P.
  
           23.1  --   Consent of KPMG Peat Marwick LLP
  
           23.2  --   Consent of Arthur Andersen LLP
  
           23.3  --   Consent of Coopers & Lybrand L.L.P.
  
           23.4  --   Consent of Vinson & Elkins L.L.P. (included in its opinion
                      filed as Exhibit 5.1 hereto)
  
  
  
  
  
                                        -3-
  <PAGE>   4
  
  ITEM 9.  UNDERTAKINGS.
  
           The Company hereby undertakes:
  
                 (1) to file, during any period in which offers or sales are
        being made, a post-effective amendment to this Registration Statement:
  
                 (i) to include any prospectus required by section 10(a)(3) of
           the Securities Act of 1933, as amended (the "Securities Act");
  
                 (ii) to reflect in the prospectus any facts or events arising
           after the effective date of the Registration Statement (or the most
           recent post-effective amendment thereof) which, individually or in
           the aggregate, represent a fundamental change in the information set
           forth in the Registration Statement; and
  
                 (iii) to include any material information with respect to the
           plan of distribution not previously disclosed in the Registration
           Statement or any material change to such information in the
           Registration Statement; provided, however, that paragraphs (1)(i) and
           (1)(ii) do not apply if the information required to be included in a
           post-effective amendment by those paragraphs is contained in periodic
           reports filed by the Company pursuant to section 13 or section 15(d)
           of the Exchange Act that are incorporated by reference in this
           Registration Statement.
  
                 (2) That, for the purposes of determining any liability under
        the Securities Act, each such post-effective amendment shall be deemed to
        be a new Registration Statement relating to the securities offered
        therein, and the offering of such securities at that time shall be deemed
        to be the initial bona fide offering thereof.
  
                 (3) To remove from registration by means of a post-effective
        amendment any of the securities being registered which remain unsold at
        the termination of the offering.
  
                 (4) That, for purposes of determining any liability under the
        Securities Act, each filing of the Company's annual report pursuant to
        section 13(a) or section 15(d) of the Exchange Act that is incorporated
        by reference in the Registration Statement shall be deemed to be a new
        Registration Statement relating to the securities offered therein, and
        the offering of such securities at that time shall be deemed to be the
        initial bona fide offering thereof.
  
                 (5) Insofar as indemnification for liabilities arising under
        the Securities Act may be permitted to directors, officers and
        controlling persons of the Company pursuant to the foregoing provisions,
        or otherwise, the Company has been advised that in the opinion of the
        Commission such indemnification is against public policy as expressed in
        the Securities Act and is, therefore, unenforceable. In the event that a
        claim for indemnification against such liabilities (other than the
        payment by the Company of expenses incurred or paid by a director,
        officer or controlling person of the Company in the successful defense of
        any action, suit or proceeding) is asserted by such director, officer or
        controlling person in connection with the securities being registered,
        the Company will, unless in the opinion of its counsel the matter has
        been settled by controlling precedent, submit to a court of appropriate
        jurisdiction the question whether such indemnification by it is against
        public policy as expressed in the Securities Act and will be governed by
        the final adjudication of such issue.
  
  
  
  
                                        -4-
  <PAGE>   5
  
                                     SIGNATURES
  
       Pursuant to the requirements of the Securities Act of 1933, as amended,
  the Company certifies that it has reasonable grounds to believe that it meets
  all of the requirements for filing on Form S-8 and has duly caused this
  Registration Statement to be signed on its behalf by the undersigned, thereunto
  duly authorized, in the City of Irving, State of Texas, on the 8th day of 1997.
  
                         PIONEER NATURAL RESOURCES COMPANY
  
  
                         By:             /s/ Scott D. Sheffield
                            ----------------------------------------------------
                                           Scott D. Sheffield
                                  President and Chief Executive Officer
  
       Pursuant to the requirements of the Securities Act, this Registration
  Statement has been signed by the following persons in the capacities and on the
  date indicated.
  
  
  <TABLE>
  <CAPTION>
            Signature                                       Capacity                          Date
            ---------                                       --------                          ----
  <S>                                        <C>                                      <C>
         /s/ Scott D. Sheffield              President, Chief Executive Officer and   September 8, 1997
  - --------------------------------------                  Director
           Scott D. Sheffield                    (Principal Executive Officer)
  
         /s/ M. Garrett Smith                  Senior Vice President--Finance and     September 8, 1997
  - --------------------------------------              Assistant Secretary       
           M. Garrett Smith                    (Principal Financial Officer and
                                                 Principal Accounting Officer)  
  
           /s/ I. Jon Brumley                       Chairman of the Board             September 8, 1997
  - --------------------------------------
            I. Jon Brumley
  
        /s/ R. Hartwell Gardner                           Director                    September 8, 1997
  - --------------------------------------
          R. Hartwell Gardner
  
         /s/ John S. Herrington                           Director                    September 8, 1997
  - --------------------------------------
          John S. Herrington
  
         /s/ Kenneth A. Hersh                             Director                    September 8, 1997
  - --------------------------------------
           Kenneth A. Hersh
  
         /s/ James L. Houghton                            Director                    September 8, 1997
  - --------------------------------------
          James L. Houghton
  
          /s/ Jerry P. Jones                              Director                    September 8, 1997
  - --------------------------------------
            Jerry P. Jones
  </TABLE>
  
  
  
  
  <PAGE>   6
  
  
  
  
  
  
  
  <TABLE>
  <S>                                        <C>                                      <C>
         /s/ T. Boone Pickens                             Director                    September 8, 1997
  - --------------------------------------
          T. Boone Pickens
  
       /s/ Richard E. Rainwater                           Director                    September 8, 1997
  - --------------------------------------
        Richard E. Rainwater
  
       /s/ Charles E. Ramsey, Jr.                         Director                    September 8, 1997
  - --------------------------------------
        Charles E. Ramsey, Jr.
  
         /s/ Arthur L. Smith                              Director                    September 8, 1997
  - --------------------------------------
           Arthur L. Smith
  
        /s/ Philip B. Smith                               Director                    September 8, 1997
  - --------------------------------------
          Philip B. Smith
  
       /s/ Robert L. Stillwell                            Director                    September 8, 1997
  - --------------------------------------
         Robert L. Stillwell
  
       /s/ Michael D. Wortley                             Director                    September 8, 1997
  - --------------------------------------
         Michael D. Wortley
  </TABLE>
  
  
  
  <PAGE>   7
  
  
                                   EXHIBIT INDEX
  
  
  <TABLE>
  <CAPTION>
          Exhibit           Description of Exhibit
          -------           ----------------------
           <S>        <C>                                            
           4.1   --   Parker & Parsley Petroleum Company Long-Term Incentive Plan
                      (filed as Exhibit No. 4.1 to Parker & Parsley's
                      Registration Statement on Form S-8, File No. 33- 38971 and
                      incorporated herein by reference).
  
           5.1   --   Opinion of Vinson & Elkins L.L.P.
  
           23.1  --   Consent of KPMG Peat Marwick LLP
  
           23.2  --   Consent of Arthur Andersen LLP
  
           23.3  --   Consent of Coopers & Lybrand L.L.P.
  
           23.4  --   Consent of Vinson & Elkins L.L.P. (included in its opinion
                      filed as Exhibit 5.1 hereto)
  
  </TABLE>
metadata_documents: [{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 20011}]
metadata_filer: {"company-data": {"conformed-name": "PIONEER NATURAL RESOURCES CO", "cik": "0001038357", "assigned-sic": "1311", "irs-number": "752702753", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "file-number": "333-35175", "film-number": "97676949"}, "business-address": {"street1": "1400 WILLIAMS SQ W", "street2": "5205 NORTH O'CONNOR BLVD", "city": "IRVING", "state": "TX", "zip": "75039", "phone": "9724449001"}, "mail-address": {"street1": "1400 WILLIAMS SQUARE WEST", "street2": "5205 NORTH O'CONNOR BLVD", "city": "IRVING", "state": "TX", "zip": "75039"}}
text: 1
     AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 8, 1997
                                                  Registration No. 333-__________
  ===============================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               Washington, D.C. 20549
  
                                 -----------------
                                      FORM S-8
                               REGISTRATION STATEMENT
                                       UNDER
                             THE SECURITIES ACT OF 1933
  
                                 -----------------
                         PIONEER NATURAL RESOURCES COMPANY
               (Exact name of registrant as specified in its charter)
  
               DELAWARE                                       75-2702753        
      (State or other jurisdiction of                       (I.R.S. Employer     
       incorporation or organization)                      Identification No.)    
                                                    
  
                             1400 WILLIAMS SQUARE WEST
                           5205 NORTH O'CONNOR BOULEVARD
                                IRVING, TEXAS 75039
            (Address of principal executive offices, including zip code)
  
                                 -----------------
  
                  PIONEER NATURAL RESOURCES COMPANY STOCK OPTIONS
  
            PARKER & PARSLEY PETROLEUM COMPANY LONG-TERM INCENTIVE PLAN
  
                              (Full title of the plan)
  
                                  MARK L. WITHROW
                             1400 WILLIAMS SQUARE WEST
                           5205 NORTH O'CONNOR BOULEVARD
                                IRVING, TEXAS 75039
                                   (972) 444-9001
             (Name, address and telephone number of agent for service)
  
                                      copy to:
                                 ROBERT L. KIMBALL
                               VINSON & ELKINS L.L.P.
                             3700 TRAMMELL CROW CENTER
                                  2001 ROSS AVENUE
                              DALLAS, TEXAS 75201-2975
                                   (214) 220-7700
  
                          CALCULATION OF REGISTRATION FEE
  =======================================================================================================================
                                                                                        Proposed
          Title of securities            Amount to be         Proposed maximum     maximum aggregate        Amount of
           to be registered               registered       offering price per unit* offering price*     registration fee
  - -----------------------------------------------------------------------------------------------------------------------
  Common Stock, $0.01 par
  value per share...................   1,328,061 shares            $39.62             $52,617,777            $15,945
  - -----------------------------------------------------------------------------------------------------------------------
  *  Estimated solely for purposes of calculating the registration fee in
     accordance with Rule 457(h) under the Securities Act of 1933 and based on
     the average of the high and low prices of the Common Stock reported on The
     New York Stock Exchange on August 29, 1997.
  
  ===============================================================================
  2
  
                                  EXPLANATORY NOTE
  
           On August 7, 1997, MESA Inc., a Texas corporation ("Mesa"), merged
  with and into the Registrant (the "Merger") pursuant to an Amended and Restated
  Agreement and Plan of Merger (the "Merger Agreement") dated as of April 6,
  1997, by and among the Registrant, Mesa, MESA Operating Co., a Delaware
  corporation and a direct wholly-owned subsidiary of Mesa, and Parker & Parsley
  Petroleum Company, a Delaware corporation ("Parker & Parsley"). Pursuant to the
  terms of the Merger Agreement, (a) the Registrant assumed each outstanding
  option to purchase common stock, par value $.01 per share, of Parker & Parsley
  ("Parker & Parsley Common Stock") granted under the Parker & Parsley Petroleum
  Company Long-Term Incentive Plan (the "Plan"), and (b) the assumed options
  became exercisable for common stock, par value $.01 per share, of the
  Registrant ("Pioneer Common Stock") at the rate of one share of Pioneer Common
  Stock for each share of Parker & Parsley Common Stock. The Registrant is
  filling this Registration Statement on Form S-8 to reflect the assumption by
  the Registrant of each such option to purchase Parker & Parsley Common Stock
  and the conversion of the options for Parker & Parsley Common Stock into options
  for Pioneer Common Stock in the Merger.
  
                                      PART II
                 INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.
  
           The following documents have been filed with the Securities and
  Exchange Commission by Pioneer Natural Resources Company, a Delaware
  corporation (the "Company"), and are incorporated herein by reference and made
  a part hereof:
  
           (a)  The Company's Registration Statement on Form S-4 (File No.
                333-26951) dated June 27, 1997; 
  
           (b)  The Company's Current Report on Form 8-K dated August 7, 1997;
                and
  
           (c)  The description of the Company's Common Stock, $0.01 par value
                per share, contained in Item 1 of the Company's Registration
                Statement on Form 8-A filed with the Commission pursuant to the
                Securities Exchange Act of 1934 (the "Exchange Act") on August
                8, 1997.
  
           All documents subsequently filed by the Company pursuant to Sections
  13(a), 13(c), 14 and 15(d) of the Exchange Act prior to the filing of a
  post-effective amendment that indicates that all securities offered have been
  sold or that deregisters all securities then remaining unsold shall also be
  deemed to be incorporated by reference herein and to be a part hereof from the
  dates of filing of such documents. Any statement contained in a document
  incorporated or deemed to be incorporated by reference herein shall be deemed
  to be modified or superseded for purposes of this Registration Statement to the
  extent that a statement contained herein or in any other subsequently filed
  document which also is or is deemed to be incorporated by reference herein
  modifies or supersedes such statement. Any statement so modified or superseded
  shall not be deemed, except as so modified or superseded, to constitute a part
  of this Registration Statement. Upon the written or oral request of any person
  to whom a copy of this Registration Statement has been delivered, the Company
  will provide without charge to such person a copy of any and all documents
  (excluding exhibits thereto unless such exhibits are specifically incorporated
  by reference into such documents) that have been incorporated by reference into
  this Registration Statement but not delivered herewith. Requests for such
  documents should be addressed to Pioneer Natural Resources Company, 1400
  Williams Square West, 5205 North O'Connor Boulevard, Irving, Texas 75039,
  Attention: Secretary, (972) 444-9001.
  
  ITEM 4.  DESCRIPTION OF SECURITIES.
  
           Not applicable.
  
  ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.
  
           Not applicable.
  
                                        -2-
  3
  
  ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  
           Article Twelfth of the Restated Certificate of Incorporation of the
  Company provides that the Company shall indemnify its officers and directors to
  the maximum extent allowed by Delaware General Corporation Law. Pursuant to
  Section 145 of the Delaware General Corporation Law, the Company generally has
  the power to indemnify its present and former directors and officers against
  expenses and liabilities incurred by them in connection with any suit to which
  they are, or are threatened to be made, a party by reason of their serving in
  those positions so long as they acted in good faith and in a manner they
  reasonably believed to be in, or not opposed to, the best interests of the
  Company, and with respect to any criminal action, so long as they had no
  reasonable cause to believe their conduct was unlawful.
  
           With respect to suits by or in the right of the Company, however,
  indemnification is generally limited to attorney's fees and other expenses and
  is not available if the person is adjudged to be liable to the Company, unless
  the court determines that indemnification is appropriate. The statute expressly
  provides that the power to indemnify authorized thereby is not exclusive of any
  rights granted under any bylaw, agreement, vote of stockholders or
  disinterested directors, or otherwise. The Company also has the power to
  purchase and maintain insurance for its directors and officers. Additionally,
  Article Twelfth of the Restated Certificate of Incorporation provides that, in
  the event that an officer or director files suit against the Company seeking
  indemnification of liabilities or expenses incurred, the burden will be on the
  Company to prove that the indemnification would not be permitted under the
  Delaware General Corporation Law.
  
           The preceding discussion of the Company's Restated Certificate of
  Incorporation and Section 145 of the Delaware General Corporation Law is not
  intended to be exhaustive and is qualified in its entirety by the Company's
  Restated Certificate of Incorporation and Section 145 of the Delaware General
  Corporation Law.
  
           The Company has entered into indemnity agreements with its directors
  and officers. Pursuant to such agreements, the Company will, to the extent
  permitted by applicable law, indemnify such persons against all expenses,
  judgments, fines and penalties incurred in connection with the defense or
  settlement of any actions brought against them by reason of the fact that they
  were directors or officers of the Company or assumed certain responsibilities
  at the direction of the Company.
  
  ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.
  
           Not applicable.
  
  ITEM 8.  EXHIBITS.
  
           Unless otherwise indicated below as being incorporated by reference to
  another filing of the Company with the Commission, each of the following
  exhibits is filed herewith:
  
           4.1   --   Parker & Parsley Petroleum Company Long-Term Incentive Plan
                      (filed as Exhibit No. 4.1 to Parker & Parsley's
                      Registration Statement on Form S-8, File No. 33- 38971 and
                      incorporated herein by reference).
  
           5.1   --   Opinion of Vinson & Elkins L.L.P.
  
           23.1  --   Consent of KPMG Peat Marwick LLP
  
           23.2  --   Consent of Arthur Andersen LLP
  
           23.3  --   Consent of Coopers & Lybrand L.L.P.
  
           23.4  --   Consent of Vinson & Elkins L.L.P. (included in its opinion
                      filed as Exhibit 5.1 hereto)
  
                                        -3-
  4
  
  ITEM 9.  UNDERTAKINGS.
  
           The Company hereby undertakes:
  
                 (1) to file, during any period in which offers or sales are
        being made, a post-effective amendment to this Registration Statement:
  
                 (i) to include any prospectus required by section 10(a)(3) of
           the Securities Act of 1933, as amended (the "Securities Act");
  
                 (ii) to reflect in the prospectus any facts or events arising
           after the effective date of the Registration Statement (or the most
           recent post-effective amendment thereof) which, individually or in
           the aggregate, represent a fundamental change in the information set
           forth in the Registration Statement; and
  
                 (iii) to include any material information with respect to the
           plan of distribution not previously disclosed in the Registration
           Statement or any material change to such information in the
           Registration Statement; provided, however, that paragraphs (1)(i) and
           (1)(ii) do not apply if the information required to be included in a
           post-effective amendment by those paragraphs is contained in periodic
           reports filed by the Company pursuant to section 13 or section 15(d)
           of the Exchange Act that are incorporated by reference in this
           Registration Statement.
  
                 (2) That, for the purposes of determining any liability under
        the Securities Act, each such post-effective amendment shall be deemed to
        be a new Registration Statement relating to the securities offered
        therein, and the offering of such securities at that time shall be deemed
        to be the initial bona fide offering thereof.
  
                 (3) To remove from registration by means of a post-effective
        amendment any of the securities being registered which remain unsold at
        the termination of the offering.
  
                 (4) That, for purposes of determining any liability under the
        Securities Act, each filing of the Company's annual report pursuant to
        section 13(a) or section 15(d) of the Exchange Act that is incorporated
        by reference in the Registration Statement shall be deemed to be a new
        Registration Statement relating to the securities offered therein, and
        the offering of such securities at that time shall be deemed to be the
        initial bona fide offering thereof.
  
                 (5) Insofar as indemnification for liabilities arising under
        the Securities Act may be permitted to directors, officers and
        controlling persons of the Company pursuant to the foregoing provisions,
        or otherwise, the Company has been advised that in the opinion of the
        Commission such indemnification is against public policy as expressed in
        the Securities Act and is, therefore, unenforceable. In the event that a
        claim for indemnification against such liabilities (other than the
        payment by the Company of expenses incurred or paid by a director,
        officer or controlling person of the Company in the successful defense of
        any action, suit or proceeding) is asserted by such director, officer or
        controlling person in connection with the securities being registered,
        the Company will, unless in the opinion of its counsel the matter has
        been settled by controlling precedent, submit to a court of appropriate
        jurisdiction the question whether such indemnification by it is against
        public policy as expressed in the Securities Act and will be governed by
        the final adjudication of such issue.
  
                                        -4-
  5
  
                                     SIGNATURES
  
       Pursuant to the requirements of the Securities Act of 1933, as amended,
  the Company certifies that it has reasonable grounds to believe that it meets
  all of the requirements for filing on Form S-8 and has duly caused this
  Registration Statement to be signed on its behalf by the undersigned, thereunto
  duly authorized, in the City of Irving, State of Texas, on the 8th day of 1997.
  
                         PIONEER NATURAL RESOURCES COMPANY
  
                         By:             /s/ Scott D. Sheffield
                            ----------------------------------------------------
                                           Scott D. Sheffield
                                  President and Chief Executive Officer
  
       Pursuant to the requirements of the Securities Act, this Registration
  Statement has been signed by the following persons in the capacities and on the
  date indicated.
  Signature                                       Capacity                          Date
            ---------                                       --------                          ----
  /s/ Scott D. Sheffield              President, Chief Executive Officer and   September 8, 1997
  - --------------------------------------                  Director
           Scott D. Sheffield                    (Principal Executive Officer)
  
         /s/ M. Garrett Smith                  Senior Vice President--Finance and     September 8, 1997
  - --------------------------------------              Assistant Secretary       
           M. Garrett Smith                    (Principal Financial Officer and
                                                 Principal Accounting Officer)  
  
           /s/ I. Jon Brumley                       Chairman of the Board             September 8, 1997
  - --------------------------------------
            I. Jon Brumley
  
        /s/ R. Hartwell Gardner                           Director                    September 8, 1997
  - --------------------------------------
          R. Hartwell Gardner
  
         /s/ John S. Herrington                           Director                    September 8, 1997
  - --------------------------------------
          John S. Herrington
  
         /s/ Kenneth A. Hersh                             Director                    September 8, 1997
  - --------------------------------------
           Kenneth A. Hersh
  
         /s/ James L. Houghton                            Director                    September 8, 1997
  - --------------------------------------
          James L. Houghton
  
          /s/ Jerry P. Jones                              Director                    September 8, 1997
  - --------------------------------------
            Jerry P. Jones
  6
  /s/ T. Boone Pickens                             Director                    September 8, 1997
  - --------------------------------------
          T. Boone Pickens
  
       /s/ Richard E. Rainwater                           Director                    September 8, 1997
  - --------------------------------------
        Richard E. Rainwater
  
       /s/ Charles E. Ramsey, Jr.                         Director                    September 8, 1997
  - --------------------------------------
        Charles E. Ramsey, Jr.
  
         /s/ Arthur L. Smith                              Director                    September 8, 1997
  - --------------------------------------
           Arthur L. Smith
  
        /s/ Philip B. Smith                               Director                    September 8, 1997
  - --------------------------------------
          Philip B. Smith
  
       /s/ Robert L. Stillwell                            Director                    September 8, 1997
  - --------------------------------------
         Robert L. Stillwell
  
       /s/ Michael D. Wortley                             Director                    September 8, 1997
  - --------------------------------------
         Michael D. Wortley
  7
  
                                   EXHIBIT INDEX
  Exhibit           Description of Exhibit
          -------           ----------------------
  4.1   --   Parker & Parsley Petroleum Company Long-Term Incentive Plan
                      (filed as Exhibit No. 4.1 to Parker & Parsley's
                      Registration Statement on Form S-8, File No. 33- 38971 and
                      incorporated herein by reference).
  
           5.1   --   Opinion of Vinson & Elkins L.L.P.
  
           23.1  --   Consent of KPMG Peat Marwick LLP
  
           23.2  --   Consent of Arthur Andersen LLP
  
           23.3  --   Consent of Coopers & Lybrand L.L.P.
  
           23.4  --   Consent of Vinson & Elkins L.L.P. (included in its opinion
                      filed as Exhibit 5.1 hereto)