EXHIBIT 32.2

                                CERTIFICATION OF
                             CHIEF FINANCIAL OFFICER
                      OF PIONEER NATURAL RESOURCES COMPANY
                         PURSUANT TO 18 U.S.C. ss. 1350

     I, Richard P. Dealy,  Executive Vice President and Chief Financial  Officer
of Pioneer Natural  Resources  Company (the "Company"),  hereby certify that the
accompanying Annual Report on Form 10-K for the year ended December 31, 2006 and
filed with the Securities and Exchange  Commission  pursuant to Section 13(a) of
the Securities Exchange Act of 1934 (the "Report") by the Company fully complies
with the requirements of that section.

     I further  certify  that the  information  contained  in the Report  fairly
presents,  in all material  respects,  the  financial  condition  and results of
operations of the Company.

                                  Name:  /s/ Richard P. Dealy
                                         ------------------------------------
                                         Richard P. Dealy, Executive Vice
                                         President and Chief Financial Officer

                                  Date:  February 19, 2007