EXHIBIT 10.6


                                    GUARANTEE

       THIS GUARANTEE dated as of April 30, 2002 (this "Guarantee"),  is entered
into by  Pioneer  Natural  Resources  USA,  Inc.,  a Delaware  corporation  (the
"Subsidiary Guarantor"). Capitalized terms used herein but not otherwise defined
have the meanings set forth in the Indenture referred to below.


                                    RECITALS:

       A.     The Subsidiary Guarantor is a  wholly-owned  subsidiary of Pioneer
Natural Resources Company, a Delaware corporation (the "Company").

       B. The Company and The Bank of New York,  a New York banking association,
as trustee (the "Trustee"),  have entered into that certain Indenture,  dated as
of  January  13,  1998,  as  supplemented  by that  certain  Third  Supplemental
Indenture  dated  as  of  April  30,  2002  (the  "Supplemental  Indenture"  and
collectively, the "Indenture"),  among the Company, the Subsidiary Guarantor and
the  Trustee,  pursuant to which the Company  has  issued,  among other  things,
$150,000,000 in aggregate  principal  amount of 7.50% Senior Notes Due 2012 (the
"Notes").

       NOW,  THEREFORE,  for good and valuable  consideration,  the  receipt and
adequacy of which is hereby acknowledged, the Subsidiary Guarantor hereby agrees
as follows:


                                    ARTICLE 1
                                    GUARANTEE

       1.1 Guarantee. The Subsidiary Guarantor hereby unconditionally guarantees
to each Holder of the Notes  authenticated  and  delivered by the Trustee and to
the Trustee and its  successors  and assigns,  irrespective  of the validity and
enforceability  of the  Indenture,  the Notes or the  obligations of the Company
thereunder,  that:  (a) the principal of,  premium,  if any, and interest on the
Notes  shall  be  promptly  paid in full  when  due,  whether  at  maturity,  by
acceleration  or  otherwise,  and  interest  on  the  overdue  principal  of and
interest,  if any, on any premium and interest on the Notes, if lawful,  and all
other obligations of the Company to the Holders or the Trustee  thereunder shall
be promptly paid in full or performed,  all in accordance  with the terms hereof
and thereof;  and (b) in case of any  extension of time of payment or renewal of
any Notes or any of such other obligations,  that same shall be promptly paid in
full when due or  performed  in  accordance  with the terms of the  extension or
renewal,  whether at stated  maturity,  by  acceleration  or otherwise.  Failing
payment when due of any amount so  guaranteed or any  performance  so guaranteed
for  whatever  reason,  the  Subsidiary  Guarantor  shall be obligated to pay or
perform the same  immediately.  The Subsidiary  Guarantor hereby agrees that its
obligations  hereunder  shall be  unconditional,  irrespective  of the validity,
regularity or  enforceability  of the Notes, the  Supplemental  Indenture or the
Indenture,  the  absence of any action to enforce  the same,  any  amendment  or
modification  of or  waiver  or  consent  by  any  Holder  with  respect  to any
provisions hereof or thereof,  the recovery of any judgment against the Company,
any action to enforce the same,  any other  circumstance  which might  otherwise
constitute  a legal or equitable  discharge  or defense of a  guarantor,  or any
change in the ownership of the Subsidiary  Guarantor.  The Subsidiary  Guarantor
hereby waives diligence, presentment, demand of payment, filing of claims with a
court in the event of  insolvency  or  bankruptcy  of the  Company  any right to
require a proceeding first against the Company,  protest, notice and all demands
whatsoever and covenants that the Subsidiary  Guarantor's  guarantee  under this
Section  shall  not  be  discharged  except  by  complete   performance  of  the
obligations of the Company and the Subsidiary  Guarantor contained in the Notes,
the  Supplemental  Indenture and the Indenture.  If any Holder or the Trustee is
required by any court or  otherwise  to return to the  Company,  the  Subsidiary
Guarantor or any custodian, trustee, liquidator or other similar official acting
in relation to either the Company or the Subsidiary Guarantor any amount paid by
any thereof to the Trustee or such Holder, the Subsidiary  Guarantor's guarantee
under this Section, to the extent theretofore discharged, shall be reinstated in
full force and  effect.  The  Subsidiary  Guarantor  agrees that it shall not be
entitled to any right of  subrogation in relation to the Holders of the Notes in
respect of any  obligations  guaranteed  hereby until payment in full in cash of
all  obligations  with respect to the Notes  guaranteed  hereby.  The Subsidiary
Guarantor further agrees that, as between itself as guarantor,  on the one hand,
and the  Holders  of the  Notes and the  Trustee,  on the  other  hand,  (x) the
maturity of the obligations  guaranteed hereby may be accelerated as provided in

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Article VI of the  Indenture  for the  purposes  of the  Subsidiary  Guarantor's
guarantee hereunder,  notwithstanding any stay,  injunction or other prohibition
preventing such  acceleration in respect of the obligations  with respect to the
Notes guaranteed  hereby and (y) in the event of any declaration of acceleration
of such obligations as provided in Article VI of the Indenture, such obligations
(whether or not due and payable) shall  forthwith  become due and payable by the
Subsidiary Guarantor for the purposes of its guarantee hereunder. The Subsidiary
Guarantor  also  agrees  to pay  any  and  all  costs  and  expenses  (including
reasonable attorney's fees and expenses) incurred by the Trustee or any Holde in
enforcing any rights under this Section.

       1.2  Continuing Guarantee;  Release;  Reinstatement. This is a continuing
guarantee  and shall  remain in full force and effect and shall be binding  upon
the Subsidiary Guarantor and its respective successors and assigns to the extent
set forth in the Indenture  until full and final payment of all of the Company's
obligations  under the Notes and the  Indenture  with  respect  to the Notes and
shall  inure to the  benefit of the  Trustee  and the Holders of Notes and their
successors and assigns and, in the event of any transfer or assignment of rights
by any  Holder  of  Notes or the  Trustee,  the  rights  and  privileges  herein
conferred  upon that party shall  automatically  extend to and be vested in such
transferee  or assignee,  all subject to the terms and  conditions  hereof.  The
Subsidiary  Guarantor  shall be released and relieved of any  obligations  under
this Guarantee upon release or other  termination of that certain Guaranty dated
as of May  31,  2000  (the  "Credit  Facility  Guarantee"),  by  the  Subsidiary
Guarantor with respect to the $575,000,000  Credit Agreement dated as of May 31,
2000 (the  "Credit  Facility"),  among the  Company,  as the  borrower,  Bank of
America,  N.A., as the administrative  agent, Credit Suisse First Boston, as the
documentation  agent,  J.P. Morgan Chase, as the syndication  agent, and certain
lenders.  The obligations of the Subsidiary Guarantor under this Guarantee shall
be  reinstated  upon the  reinstatement  of the  obligations  of the  Subsidiary
Guarantor  under the Credit  Facility  Guarantee  and the  Subsidiary  Guarantor
hereby agrees to execute a guarantee substantially in the form of this Guarantee
upon such  reinstatement.  Any  refinancing,  refunding,  extension,  renewal or
replacement (or successive  refinancings,  refundings,  extensions,  renewals or
replacements),  as a whole,  or in part,  of the  Credit  Facility  shall not be
deemed a release or other  termination of the Credit  Facility  Guarantee if the
Subsidiary  Guarantor  provides a guarantee  with  respect to such  refinancing,
refunding, extension, renewal or replacement in substantially the same form, and
on substantially the same terms, as the Credit Facility Guarantee.  It is hereby
understood  and agreed that the Credit  Facility  may be  refinanced,  refunded,
extended,   renewed  or  replaced  (through  one  or  more  such   refinancings,
refundings,  extensions, renewals or replacements), as a whole, or in part, from
time to time after the termination of the Credit Facility.

                                    ARTICLE 2
                                  MISCELLANEOUS

       2.1 Headings.  The headings contained in this Guarantee are for reference
purposes only and shall not affect in any way the meaning or  interpretation  of
this Guarantee.

       2.2 Severability.  If any  provision in this  Guarantee shall be invalid,
illegal or  unenforceable,  the  validity,  legality and  enforceability  of the
remaining provisions shall not in any way be affected or impaired thereby.

       2.3    Governing Law.  This Guarantee shall be  governed by and construed
in  accordance  with  the laws of the  State  of New  York,  without  regard  to
principles of conflicts of laws.

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       IN  WITNESS  WHEREOF,  the  undersigned has  caused this  Guarantee to be
signed by its duly authorized officer as of the date first above written.

                                  PIONEER NATURAL RESOURCES USA, INC.

                                  By:  /s/ Richard P. Dealy
                                     ---------------------------------------
                                       Richard P. Dealy
                                       Vice President and Chief Accounting
                                       Officer


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