1
                                                                     EXHIBIT 4.5
   
             Incorporated Under the Laws of       SERIES B CONVERTIBLE PREFERRED
                 The State of Delaware                 PAR VALUE $.01

NUMBER                                                                    SHARES



                                                     
     This Certificate is transferable in                              CUSIP 000000 00 0
New York, New York and Jersey City, New Jersey          See reverse for certain definitions and legends


                       PIONEER NATURAL RESOURCES COMPANY

         THIS CERTIFIES THAT





         IS THE OWNER OF

           FULLY PAID AND NON-ASSESSABLE SHARES OF THE SERIES B CONVERTIBLE
                                   PREFERRED STOCK OF

SEAL     Pioneer Natural Resources Company (hereinafter called the Corporation),
         transferable on the books of the Corporation holder hereof in person or
         by duly authorized attorney upon surrender of this certificate properly
         endorsed.  This certificate is not valid unless countersigned by
         Transfer Agent and registered by the Registrar.

         Witness, the seal of the Corporation and the signatures of its duly
         authorized officers.


/s/ S. SHEFHELD
PRESIDENT AND CHIEF EXECUTIVE OFFICER              DATED

                                                   COUNTERSIGNED AND REGISTERED:
                                                   CONTINENTAL STOCK TRANSFER &
                                                   TRUST COMPANY
                                                            TRANSFER AGENT
                                                            AND REGISTRAR
/s/ M. WITHROW                                     BY
EXECUTIVE VICE PRESIDENT AND SECRETARY                      Authorized Signature
    





   2
                       PIONEER NATURAL RESOURCES COMPANY

         The Corporation is authorized to issue shares of more than one class
and to issue shares in more than one series of at least one class.  The
Corporation will furnish without charge to each stockholder who so requests a
statement of the powers, designations, preferences and relative, participating,
optional or other special right of each class of stock or series thereof of the
Corporation and the qualifications, limitations or restrictions of such
preferences and/or rights.  Such request may be made to the Corporation or to
the transfer agent.

         The following abbreviations, when used in the inscription on the face
of this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:



                                                     
         TEN COM - as tenants in common                 UNIF GIFT MIN ACT - __________Custodian _____________
         TEN ENT - as tenants by the entireties                              (Cust)               (Minor)
         JT TEN - as joint tenants with right of                               under Uniform Gifts to Minors
                 survivorship and not as tenants                               Act _______________
                 in common                                                           ([____])



     Additional abbreviations may also be used though not in the above list.

         For value received, ____________________________ hereby sell, assign
and transfer unto

            Please insert Social Security or other
            Identifying Number of Assignee

            -----------------------------

- --------------------------------------------------------------------------------
            Please print or typewrite name and address of Assignee.

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------

- --------------------------------------------------------------------------------

                                                                    shares of
- --------------------------------------------------------------------
capital stock represented by the within Certificate, and do hereby irrevocably
constitute and appoint _____________________________________________ Attorney
to transfer the said stock on the books of the within-named Corporation with
full power of substitution in the premises.

Dated 
      ----------------------------

                                             X
                                              ---------------------------------
           NOTICE:                                            (Signature)
   THE SIGNATURES TO THE ASSIGNMENT
   MUST CORRESPOND WITH THE NAME(S)
   AS WRITTEN UPON THE FACE OF THE
   CERTIFICATE IN EVERY PARTICULAR           X                            
   WITHOUT ALTERNATION OR ENLARGEMENT         ---------------------------------
   OR ANY CHANGE WHATEVER.                                    (Signature)
                                             The signature(s) would be
                                             guaranteed by an "eligible
                                             guarantor institution" as defined
                                             in _____ under The Securities
                                             Exchange Act of 1934 as amended. 
                                             SIGNATURE(S) GUARANTEED BY:


      AMERICAN BANKNOTE COMPANY              Production Coordinator 
                                             - Belinda Beck - [__________]
        89 Blair Mill Road                   Proof of June 10, 1997
        Horsham, PA  79044                            PIONEER
           [_________]                             [_____________]

      Sales Person                 M. Garrett       Opr.   [___]          REV. 1
                 [________________]                         [__________________]