EXHIBIT 31.2

                      CHIEF FINANCIAL OFFICER CERTIFICATION

     I, Richard P. Dealy, certify that:

     1.     I have reviewed  this annual report  on Form 10-K of Pioneer Natural
            Resources Company;

     2.     Based on  my knowledge,  this  report  does not  contain  any untrue
            statement  of a  material  fact  or omit  to state  a material  fact
            necessary to  make the  statements made,  in light of  circumstances
            under which such  statements were made,  not misleading with respect
            to the period covered by this report;

     3.     Based on my knowledge, the financial statements, and other financial
            information  included in this report, fairly present in all material
            respects the  financial condition,  results of  operations  and cash
            flows of  the registrant as of,  and for,  the periods  presented in
            this report;

     4.     The registrant's  other certifying officer and I are responsible for
            establishing and maintaining  disclosure controls and procedures (as
            defined in Exchange Act Rules 13a-15(e)  and 15d-15(e)) and internal
            control over financial reporting  (as defined in  Exchange Act Rules
            13a-15(f) and 15d-15(f)) for the registrant and have:

            (a)   Designed such  disclosure controls  and procedures,  or caused
                  such  disclosure controls  and procedures to be designed under
                  our supervision, to ensure  that material information relating
                  to the registrant, including its consolidated subsidiaries, is
                  made known to us by others within those entities, particularly
                  during the period in which this report is being prepared;

            (b)   Designed such  internal control  over financial  reporting, or
                  caused such  internal control  over financial  reporting to be
                  designed  under   our  supervision,  to   provide   reasonable
                  assurance regarding the reliability of financial reporting and
                  the preparation of financial  statements for external purposes
                  in accordance with generally accepted accounting principles;

            (c)   Evaluated the  effectiveness  of the  registrant's  disclosure
                  controls and  procedures  and  presented  in  this  report our
                  conclusions about the effectiveness of the disclosure controls
                  and procedures,  as of the end of  the period covered  by this
                  report based on such evaluation; and

            (d)   Disclosed in  this  report  any  change  in  the  registrant's
                  internal control over financial reporting that occurred during
                  the registrant's  most recent fiscal quarter (the registrant's
                  fourth  fiscal quarter  in the case of  an annual report) that
                  has materially affected, or is reasonably likely to materially
                  affect, the registrant's internal control over financial
                  reporting; and

     5.     The registrant's  other  certifying   officer and  I have disclosed,
            based  on  our  most  recent  evaluation  of  internal  control over
            financial  reporting,  to the  registrant's  auditors and  the audit
            committee  of  the  registrant's  board  of  directors  (or  persons
            performing the equivalent functions):

            (a)   All significant  deficiencies and  material  weaknesses in the
                  design  or  operation  of  internal   control  over  financial
                  reporting which  are reasonably likely to adversely affect the
                  registrant's ability to record, process,  summarize and report
                  financial information; and

            (b)   Any fraud,  whether or not material,  that involves management
                  or  other  employees  who  have  a  significant  role  in  the
                  registrant's internal control over financial reporting.

February 16, 2005
                             /s/ Richard P. Dealy
                           --------------------------------------------
                           Richard P. Dealy, Executive Vice President
                           and Chief Financial Officer