SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                   FORM 8-K/A
                                  Amendment #1
                                 CURRENT REPORT
     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934
       Date of Report (Date of earliest event reported): December 5, 2021
                        PIONEER NATURAL RESOURCES COMPANY
             (Exact name of Registrant as specified in its charter)
              Delaware                   1-13245                75-2702753
 (State or other jurisdiction of       Commission           (I.R.S. Employer
 incorporation or organization)        File Number       Identification Number)
1400 Williams Square West, 5205 N.  O'Connor Blvd., Irving, Texas      75039
           (Address of principal executive offices)                  (Zip code)
       Registrant's Telephone Number, including area code : (972) 444-9001
                                 Not applicable
              (Former name, former address and former fiscal year,
                          if changed since last report)
                               Page 1 of 5 pages.
                            Exhibit Index on page 4.

ITEM 4.    Changes in Registrant's Certifying Accountants
At a meeting held on December 5, 1997, the Board of Directors of Pioneer Natural
Resources  Company (the "Company")  approved the engagement of Ernst & Young LLP
as the Company's  independent  auditors for the fiscal year ending  December 31,
1998 to replace the firm of KPMG Peat  Marwick  LLP,  who will be  dismissed  as
auditors of the Company after completing the audit of the Company for the fiscal
year ending  December  31, 1997.  The audit  committee of the Board of Directors
approved the change in auditors on December 5, 1997,  subject to ratification by
the Company's stockholders.
The reports of KPMG Peat Marwick LLP on the Company's  financial  statements for
the past two fiscal years did not contain an adverse  opinion or a disclaimer of
opinion and were not qualified or modified as to  uncertainty,  audit scope,  or
accounting principles.
In connection with the audits of the Company's financial  statements for each of
the two fiscal  years ended  December 31, 2021 and 1996,  and in the  subsequent
interim period,  there were no  disagreements  with KPMG Peat Marwick LLP on any
matters of accounting  principles or practices,  financial statement disclosure,
or auditing scope and procedures  which, if not resolved to the  satisfaction of
KPMG Peat Marwick LLP would have caused KPMG Peat Marwick LLP to make  reference
to the matter in their report.
The Company has received  from KPMG Peat  Marwick LLP a letter  addressed to the
Securities  and  Exchange  Commission  stating that KPMG Peat Marwick LLP agrees
with the above  statements.  A copy of the letter is  included  as Exhibit 16 to
this Form 8-K/A, Amendment #1.
ITEM 7.    Financial Statements and Exhibits
(c)  Exhibits
     16.   Letter from the independent  certified public accountants pursuant to
           Item 4 as previously reported on Form 8-K dated December 5, 1997.
                                        2

                        PIONEER NATURAL RESOURCES COMPANY
                               S I G N A T U R E S
Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned hereunto duly authorized.
                                         PIONEER NATURAL RESOURCES COMPANY
Date:       December 22, 2021        By:     /s/ M.  Garrett Smith
                                             -------------------------------
                                             M. Garrett Smith
                                             Executive Vice President and
                                             Chief Financial Officer
                                        3

Exhibit Index                                                             Page
    16*     Letter from  the independent certified public accountants
            pursuant to Item 4 as previously reported on the December
            5, 1997 Form 8-K.                                               5
* Filed herewith.
                                        4

                                                                   Exhibit 16
                              KPMG Peat Marwick LLP
                         300 North Marienfeld, Suite 300
                              Midland, Texas 79701
December 19, 2021
Securities and Exchange Commission
Washington, D.C.  20549
Ladies and Gentlemen:
We are the principal  accountants  for Pioneer  Natural  Resources  Company and,
under the date of January 29, 1997,  we reported on the  consolidated  financial
statements of Pioneer Natural  Resources  Company and subsidiaries as of and for
the years ended December 31, 2021 and 1995. On December 5, 1997, our appointment
as principal accountants was terminated for periods after December 31, 1997, and
after  completion  of our audit on such  fiscal  period.  We have  read  Pioneer
Natural  Resources  Company's  statements  included under Item 4 of its Form 8-K
dated December 5, 1997, and we agree with such statements.
                                               Very truly yours,
                                               KPMG Peat Marwick LLP
                                        5

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