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)
  
                                --------------------
  
                          1996 INCENTIVE PLAN OF MESA INC.
  
                              (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............... 510,000 shares          $38.30             $19,533,000          $5,920
  - ----------------------------------------------------------------------------------------------------------
  </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 28, 1997.
  
  ================================================================================
  <PAGE>   2
  
                                      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 From 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.
  
  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
  
                                        -2-
  
  <PAGE>   3
  
  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   -- 1996 Incentive Plan of MESA Inc. (filed as Exhibit No. 10.28 to
                the Company's Registration Statement on Form S-4, File No.
                333-26951, 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.
  
       23.2  -- Consent of Vinson & Elkins L.L.P. (included in its opinion filed 
                as Exhibit 5.1 hereto)
  
       24.1  -- Powers of Attorney
  
  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
  
  
                                        -3-
  
  <PAGE>   4
  
  
  
                 (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 5th day of
  September, 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 5, 1997
  - ----------------------------------                  Director
         Scott D. Sheffield               (Principal Executive Officer)
  
      /s/ M. Garrett Smith              Senior Vice President--Finance and       September 5, 1997
  - ----------------------------------             Assistant Secretary
          M. Garrett Smith           (Principal Financial Officer and Principal
                                                 Accounting Officer)
  
       /s/ I. Jon Brumley                      Chairman of the Board             September 5, 1997
  - ----------------------------------
           I. Jon Brumley
  
     /s/ R. Hartwell Gardner                         Director                    September 5, 1997
  - ----------------------------------
         R. Hartwell Gardner
  
     /s/ John S. Herrington                          Director                    September 5, 1997
  - ----------------------------------
         John S. Herrington
  
      /s/ Kenneth A. Hersh                           Director                    September 5, 1997
  - ----------------------------------
          Kenneth A. Hersh
  
      /s/ James L. Houghton                          Director                    September 5, 1997
  - ----------------------------------
          James L. Houghton
  </TABLE>
  
  
  <PAGE>   6
  
  
  
  
  <TABLE>
  <S>                                <C>                                         <C> 
       /s/ Jerry P. Jones                            Director                    September 5, 1997
  - ----------------------------------
           Jerry P. Jones
  
      /s/ T. Boone Pickens                           Director                    September 5, 1997
  - ----------------------------------
          T. Boone Pickens
  
    /s/ Richard E. Rainwater                         Director                    September 5, 1997
  - ----------------------------------
        Richard E. Rainwater
  
   /s/ Charles E. Ramsey, Jr.                        Director                    September 5, 1997
  - ----------------------------------
       Charles E. Ramsey, Jr.
  
       /s/ Arthur L. Smith                           Director                    September 5, 1997
  - ----------------------------------
           Arthur L. Smith
  
       /s/ Philip B. Smith                           Director                    September 5, 1997
  - ----------------------------------
           Philip B. Smith
  
     /s/ Robert L. Stillwell                         Director                    September 5, 1997
  - ----------------------------------
         Robert L. Stillwell
  
     /s/ Michael D. Wortley                          Director                    September 5, 1997
  - ----------------------------------
         Michael D. Wortley
  </TABLE>
  
  
  
  
  <PAGE>   7
  
  
  
                                   EXHIBIT INDEX
  
  
  <TABLE>
  <CAPTION>
     Exhibit           Description of Exhibit
     -------           ----------------------
     <S>     <C>
       4.1   -- 1996 Incentive Plan of MESA Inc. (filed as Exhibit No. 10.28 to
                the Company's Registration Statement on Form S-4, File No.
                333-26951, 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.
  
       23.2  -- Consent of Vinson & Elkins L.L.P. (included in its opinion filed 
                as Exhibit 5.1 hereto)
  
       24.1  -- Powers of Attorney
  </TABLE>
metadata_documents: [{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 18028}]
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": "333-35085", "film-number": "97676407"}, "business-address": {"street1": "1400 WILLIAMS SQUARE WEST", "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)
  
                                --------------------
  
                          1996 INCENTIVE PLAN OF MESA INC.
  
                              (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............... 510,000 shares          $38.30             $19,533,000          $5,920
  - ----------------------------------------------------------------------------------------------------------
  *    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 28, 1997.
  
  ================================================================================
  2
  
                                      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 From 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.
  
  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
  
                                        -2-
  3
  
  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   -- 1996 Incentive Plan of MESA Inc. (filed as Exhibit No. 10.28 to
                the Company's Registration Statement on Form S-4, File No.
                333-26951, 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.
  
       23.2  -- Consent of Vinson & Elkins L.L.P. (included in its opinion filed 
                as Exhibit 5.1 hereto)
  
       24.1  -- Powers of Attorney
  
  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
  
                                        -3-
  4
  
                 (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 5th day of
  September, 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 5, 1997
  - ----------------------------------                  Director
         Scott D. Sheffield               (Principal Executive Officer)
  
      /s/ M. Garrett Smith              Senior Vice President--Finance and       September 5, 1997
  - ----------------------------------             Assistant Secretary
          M. Garrett Smith           (Principal Financial Officer and Principal
                                                 Accounting Officer)
  
       /s/ I. Jon Brumley                      Chairman of the Board             September 5, 1997
  - ----------------------------------
           I. Jon Brumley
  
     /s/ R. Hartwell Gardner                         Director                    September 5, 1997
  - ----------------------------------
         R. Hartwell Gardner
  
     /s/ John S. Herrington                          Director                    September 5, 1997
  - ----------------------------------
         John S. Herrington
  
      /s/ Kenneth A. Hersh                           Director                    September 5, 1997
  - ----------------------------------
          Kenneth A. Hersh
  
      /s/ James L. Houghton                          Director                    September 5, 1997
  - ----------------------------------
          James L. Houghton
  6
  /s/ Jerry P. Jones                            Director                    September 5, 1997
  - ----------------------------------
           Jerry P. Jones
  
      /s/ T. Boone Pickens                           Director                    September 5, 1997
  - ----------------------------------
          T. Boone Pickens
  
    /s/ Richard E. Rainwater                         Director                    September 5, 1997
  - ----------------------------------
        Richard E. Rainwater
  
   /s/ Charles E. Ramsey, Jr.                        Director                    September 5, 1997
  - ----------------------------------
       Charles E. Ramsey, Jr.
  
       /s/ Arthur L. Smith                           Director                    September 5, 1997
  - ----------------------------------
           Arthur L. Smith
  
       /s/ Philip B. Smith                           Director                    September 5, 1997
  - ----------------------------------
           Philip B. Smith
  
     /s/ Robert L. Stillwell                         Director                    September 5, 1997
  - ----------------------------------
         Robert L. Stillwell
  
     /s/ Michael D. Wortley                          Director                    September 5, 1997
  - ----------------------------------
         Michael D. Wortley
  7
  
                                   EXHIBIT INDEX
  Exhibit           Description of Exhibit
     -------           ----------------------
  4.1   -- 1996 Incentive Plan of MESA Inc. (filed as Exhibit No. 10.28 to
                the Company's Registration Statement on Form S-4, File No.
                333-26951, 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.
  
       23.2  -- Consent of Vinson & Elkins L.L.P. (included in its opinion filed 
                as Exhibit 5.1 hereto)
  
       24.1  -- Powers of Attorney