UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D. C. 20549


                                    FORM 10-Q


                Quarterly Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934


                For the quarterly period ended September 30, 2001


                         Commission File No. 33-26097-07


                           PARKER & PARSLEY 90-B, L.P.
                          -----------------------------
             (Exact name of Registrant as specified in its charter)


                 Delaware                                     75-2329287
    -----------------------------------------           ---------------------
       (State or other jurisdiction of                     (I.R.S. Employer
        incorporation or organization)                  Identification Number)


5205 N. O'Connor Blvd., Suite 1400, 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)

Indicate by check mark whether the Registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the  preceding 12 months (or for such  shorter  period that the  Registrant  was
required  to file  such  reports),  and  (2) has  been  subject  to such  filing
requirements for the past 90 days.

                                Yes / x / No / /









                           PARKER & PARSLEY 90-B, L.P.

                                TABLE OF CONTENTS


                                                                        Page
                          Part I. Financial Information

Item 1.     Financial Statements

            Balance Sheets as of September 30, 2001 and
               December 31, 2000......................................    3

            Statements of Operations for the three and nine
              months ended September 30, 2001 and 2000................    4

            Statement of Partners' Capital for the nine months
              ended September 30, 2001................................    5

            Statements of Cash Flows for the nine months ended
              September 30, 2001 and 2000.............................    6

            Notes to Financial Statements.............................    7

Item 2.     Management's Discussion and Analysis of Financial
              Condition and Results of Operations.....................    8


                           Part II. Other Information

Item 6.     Exhibits and Reports on Form 8-K..........................   12

            Signatures................................................   13


                                        2





                           PARKER & PARSLEY 90-B, L.P.
                        (A Delaware Limited Partnership)

                          Part I. Financial Information

Item 1.     Financial Statements

                                 BALANCE SHEETS


                                                  September 30,   December 31,
                                                       2001           2000
                                                  -------------   ------------
                                                   (Unaudited)
                 ASSETS
                                                            
Current assets:
  Cash                                            $    798,150    $    364,895
  Accounts receivable - oil and gas sales              393,565         568,283
                                                   -----------     -----------
         Total current assets                        1,191,715         933,178
                                                   -----------     -----------
Oil and gas properties - at cost,  based on the
  successful efforts accounting method              25,946,724      26,110,930
Accumulated depletion                              (21,988,768)    (21,899,717)
                                                   -----------     -----------
         Net oil and gas properties                  3,957,956       4,211,213
                                                   -----------     -----------
                                                  $  5,149,671    $  5,144,391
                                                   ===========     ===========
LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
  Accounts payable - affiliate                    $    137,433    $     42,091

Partners' capital:
  Managing general partner                              50,126          51,027
  Limited partners (32,264 interests)                4,962,112       5,051,273
                                                   -----------     -----------
                                                     5,012,238       5,102,300
                                                   -----------     -----------
                                                  $  5,149,671    $  5,144,391
                                                   ===========     ===========



The financial information included as of September 30, 2001 has been prepared by
 the managing general partner without audit by independent public accountants.

  The accompanying notes are an integral part of these financial statements.

                                        3





                           PARKER & PARSLEY 90-B, L.P.
                        (A Delaware Limited Partnership)

                            STATEMENTS OF OPERATIONS
                                   (Unaudited)




                                           Three months ended          Nine months ended
                                              September 30,               September 30,
                                        ------------------------    ------------------------
                                           2001          2000          2001          2000
                                        ----------    ----------    ----------    ----------
                                                                      
Revenues:
  Oil and gas                           $  814,193    $1,098,786    $2,883,717    $2,962,304
  Interest                                   5,341         9,281        19,499        22,423
  Gain on disposition of assets             11,959           -          20,242         5,487
                                         ---------     ---------     ---------     ---------
                                           831,493     1,108,067     2,923,458     2,990,214
                                         ---------     ---------     ---------     ---------
Costs and expenses:
  Oil and gas production                   456,072       368,259     1,221,395     1,120,284
  General and administrative                22,471        37,886        84,405        96,797
  Impairment of oil and gas properties      30,575           -          30,575           -
  Depletion                                 85,177        67,785       232,270       210,132
  Abandoned property                           213           -           8,509           -
                                         ---------     ---------     ---------     ---------
                                           594,508       473,930     1,577,154     1,427,213
                                         ---------     ---------     ---------     ---------
Net income                              $  236,985    $  634,137    $1,346,304    $1,563,001
                                         =========     =========     =========     =========
Allocation of net income:
  Managing general partner              $    2,370    $    6,341    $   13,463    $   15,630
                                         =========     =========     =========     =========
  Limited partners                      $  234,615    $  627,796    $1,332,841    $1,547,371
                                         =========     =========     =========     =========
Net income per limited
  partnership interest                  $     7.27    $    19.46    $    41.31    $    47.96
                                         =========     =========     =========     =========




         The financial information included herein has been prepared by
    managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.

                                        4





                           PARKER & PARSLEY 90-B, L.P.
                        (A Delaware Limited Partnership)

                         STATEMENT OF PARTNERS' CAPITAL
                                   (Unaudited)





                                       Managing
                                       general       Limited
                                       partner       partners         Total
                                      ----------    -----------    -----------


                                                          
Balance at January 1, 2001            $   51,027    $ 5,051,273    $ 5,102,300

    Distributions                        (14,364)    (1,422,002)    (1,436,366)

    Net income                            13,463      1,332,841      1,346,304
                                       ---------     ----------     ----------

Balance at September 30, 2001         $   50,126    $ 4,962,112    $ 5,012,238
                                       =========     ==========     ==========






         The financial information included herein has been prepared by
    managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.

                                        5





                           PARKER & PARSLEY 90-B, L.P.
                        (A Delaware Limited Partnership)

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)




                                                         Nine months ended
                                                           September 30,
                                                     --------------------------
                                                         2001           2000
                                                     -----------    -----------
                                                              
Cash flows from operating activities:
   Net income                                        $ 1,346,304    $ 1,563,001
   Adjustments to reconcile net income to net
     cash provided by operating activities:
       Impairment of oil and gas properties               30,575            -
       Depletion                                         232,270        210,132
       Gain on disposition of assets                     (20,242)        (5,487)
   Changes in assets and liabilities:
       Accounts receivable                               174,718        (98,986)
       Accounts payable                                   95,342         54,488
                                                      ----------     ----------
         Net cash provided by operating activities     1,858,967      1,723,148
                                                      ----------     ----------
Cash flows from investing activities:
   Additions to oil and gas properties                    (9,898)       (38,547)
   Proceeds from asset dispositions                       20,552          5,487
                                                      ----------     ----------
         Net cash provided by (used in) investing
           activities                                     10,654        (33,060)
                                                      ----------     ----------
Cash flows used in financing activities:
   Cash distributions to partners                     (1,436,366)    (1,619,198)
                                                      ----------     ----------
Net increase in cash                                     433,255         70,890
Cash at beginning of period                              364,895        311,017
                                                      ----------     ----------
Cash at end of period                                $   798,150    $   381,907
                                                      ==========     ==========





         The financial information included herein has been prepared by
  the managing general partner without audit by independent public accountants.

   The accompanying notes are an integral part of these financial statements.

                                        6





                           PARKER & PARSLEY 90-B, L.P.
                        (A Delaware Limited Partnership)

                          NOTES TO FINANCIAL STATEMENTS
                               September 30, 2001
                                   (Unaudited)


Note 1.     Organization and nature of operations

Parker &  Parsley  90-B,  L.P.  (the  "Partnership")  is a  limited  partnership
organized in 1990 under the laws of the State of Delaware.

The  Partnership  engages in oil and gas development and production in Texas and
is not involved in any industry segment other than oil and gas.

Note 2.     Basis of presentation

In  the  opinion  of  management,  the  unaudited  financial  statements  of the
Partnership  as of  September  30, 2001 and for the three and nine months  ended
September 30, 2001 and 2000 include all adjustments and accruals consisting only
of  normal  recurring  accrual  adjustments  which  are  necessary  for  a  fair
presentation  of the results for the interim  period.  These interim results are
not necessarily indicative of results for a full year. Certain reclassifications
may have been made to the September 30, 2000 financial  statements to conform to
the September 30, 2001 financial statement presentations.

Certain  information  and footnote  disclosures  normally  included in financial
statements prepared in accordance with generally accepted accounting  principles
have been  condensed  or  omitted  in this Form 10-Q  pursuant  to the rules and
regulations of the Securities and Exchange Commission.  The financial statements
should  be read in  conjunction  with the  financial  statements  and the  notes
thereto  contained in the  Partnership's  Report on Form 10-K for the year ended
December 31, 2000, as filed with the Securities and Exchange Commission,  a copy
of which is available upon request by writing to Rich Dealy,  Vice President and
Chief Accounting  Officer,  5205 North O'Connor  Boulevard,  Suite 1400, Irving,
Texas 75039-3746.

Note 3.     Impairment of long-lived assets

In  accordance  with  Statement  of  Financial  Accounting  Standards  No.  121,
"Accounting for the Impairment of Long-Lived Assets and for Long-Lived Assets to
be Disposed Of" ("SFAS  121"),  the  Partnership  reviews its proved oil and gas
properties for impairment  whenever events and circumstances  indicate a decline
in the  recoverability  of the carrying value of the  Partnership's  oil and gas
properties.  The Partnership has estimated the expected future cash flows of its
oil and gas properties as of September 30, 2001, based on proved  reserves,  and
compared such estimated  future cash flows to the respective  carrying amount of
the oil and gas  properties to determine if the carrying  amounts were likely to
be  recoverable.  For those proved oil and gas properties for which the carrying
amount exceeded the estimated future cash flows, an impairment was determined to
exist; therefore,  the Partnership adjusted the carrying amount of those oil and
gas properties  to their fair  value as determined by discounting their expected

                                        7





future cash flows at a discount rate commensurate with the risks involved in the
industry.  As  a  result,  the  Partnership  recognized  a  non-cash  impairment
provision  of $30,575  related to its proved oil and gas  properties  during the
nine months ended September 30, 2001.

Note 4.     Proposal to acquire Partnership

On October 22,  2001,  Pioneer  Natural  Resources  Company  ("Pioneer")  mailed
definitive materials (the "proxy  statement/prospectus") to solicit the approval
of the limited partners of the  Partnership.  Pioneer has valued the Partnership
interest at  $8,900,613 of which  $8,788,939 is allocated to the  non-affiliated
limited partners. If a majority of the limited partners approve the transaction,
the limited  partners  will  receive  their value in the form of Pioneer  common
stock.

Item 2.     Management's Discussion and Analysis of Financial Condition
               and Results of Operations (1)

Results of Operations

Nine months ended September 30, 2001 compared with nine months ended September
   30, 2000

Revenues:

The Partnership's  oil and gas revenues  decreased 3% to $2,883,717 for the nine
months ended September 30, 2001 as compared to $2,962,304 for the same period in
2000. The decrease in revenues  resulted from lower average prices  received for
oil and natural  gas liquids  ("NGLs")  and a decline in  production,  offset by
higher average prices  received for gas. For the nine months ended September 30,
2001,  69,840 barrels of oil, 27,890 barrels of NGLs and 140,294 mcf of gas were
sold, or 121,112 barrel of oil equivalents  ("BOEs").  For the nine months ended
September 30, 2000,  73,699  barrels of oil,  35,181 barrels of NGLs and 135,699
mcf of gas were sold, or 131,497 BOEs. Due to the decline characteristics of the
Partnership's  oil and gas  properties,  management  expects a certain amount of
decline  in  production  in the  future  until  the  Partnership's  economically
recoverable reserves are fully depleted.

The average price received per barrel of oil decreased $1.07, or 4%, from $28.68
for the nine months  ended  September  30, 2000 to $27.61 for the same period in
2001. The average price received per barrel of NGLs decreased  $.33, or 2%, from
$14.66  during the nine months ended  September  30, 2000 to $14.33 for the same
period in 2001.  The average  price  received per mcf of gas  increased 62% from
$2.45 for the nine months ended  September 30, 2000 to $3.96 for the same period
in 2001 The market price for oil and gas has been extremely volatile in the past
decade and management  expects a certain amount of volatility to continue in the
foreseeable  future.  The  Partnership may therefore sell its future oil and gas
production at average prices lower or higher than that received  during the nine
months ended September 30, 2001.

Gains on disposition of assets of $20,242 and $5,487 were recognized  during the
nine months ended September 30, 2001 and 2000, respectively. The gain recognized
during the period ended  September 30, 2001 consisted of $19,074  salvage income
from one  well plugged and  abandoned  in the  current  period and  $1,168  from

                                        8





equipment  credits  received on one fully  depleted  well.  The gain  recognized
during  the  period  ended  September  30,  2000  was  derived  from the sale of
equipment on one fully  depleted well.  Abandoned  property costs of $8,509 were
incurred during the nine months ended September 30, 2001 to plug one well in the
current period.

Costs and Expenses:

Total costs and  expenses  increased  to  $1,577,154  for the nine months  ended
September  30, 2001 as compared to  $1,427,213  for the same period in 2000,  an
increase of $149,941,  or 11%.  The increase was due to increases in  production
costs,  the  impairment  of oil  and gas  properties,  depletion  and  abandoned
property  costs,  offset by a decline in  general  and  administrative  expenses
("G&A").

Production  costs were  $1,221,395 for the nine months ended  September 30, 2001
and  $1,120,284  for the  same  period  in 2000,  resulting  in an  increase  of
$101,111,  or 9%. The increase was  primarily due to higher ad valorem taxes and
additional  workover  and well  maintenance  costs  incurred to  stimulate  well
production.

G&A's  components are independent  accounting and engineering  fees and managing
general partner personnel and operating costs. During this period, G&A decreased
13% from $96,797 for the nine months ended September 30, 2000 to $84,405 for the
same period in 2001, primarily due to a lower percentage of the managing general
partner's  G&A being  allocated  (limited  to 3% of oil and gas  revenues)  as a
result of decreased oil and gas revenues.

In  accordance  with  Statement  of  Financial  Accounting  Standards  No.  121,
"Accounting for the Impairment of Long-Lived Assets and for Long-Lived Assets to
be Disposed Of" ("SFAS  121"),  the  Partnership  reviews its proved oil and gas
properties for impairment  whenever events and circumstances  indicate a decline
in the  recoverability  of the carrying value of the  Partnership's  oil and gas
properties.  The Partnership has estimated the expected future cash flows of its
oil and gas properties as of September 30, 2001, based on proved  reserves,  and
compared such estimated  future cash flows to the respective  carrying amount of
the oil and gas  properties to determine if the carrying  amounts were likely to
be  recoverable.  For those proved oil and gas properties for which the carrying
amount exceeded the estimated future cash flows, an impairment was determined to
exist; therefore,  the Partnership adjusted the carrying amount of those oil and
gas properties to their fair value as determined by  discounting  their expected
future cash flows at a discount rate commensurate with the risks involved in the
industry.  As  a  result,  the  Partnership  recognized  a  non-cash  impairment
provision  of $30,575  related to its proved oil and gas  properties  during the
nine months ended September 30, 2001.

Depletion was $232,270 for the nine months ended  September 30, 2001 as compared
to $210,132 for the same period in 2000, representing an increase of $22,138, or
11%. This increase was primarily due to a decline in proved  reserves during the
period ended September 30, 2001 due to lower commodity prices as compared to the
same period in 2000,  offset by a reduction in the  Partnership's net depletable
basis from charges taken in accordance  with SFAS 121 during the fourth  quarter
of 2000 and by a decrease in oil production of 3,859 barrels for the nine months
ended September 30, 2001 as compared to the same period in 2000.


                                        9





Three months ended September 30, 2001 compared with three months ended September
   30, 2000

Revenues:

The Partnership's  oil and gas revenues  decreased 26% to $814,193 for the three
months ended September 30, 2001 as compared to $1,098,786 for the same period in
2000. The decrease in revenues resulted from lower average prices received and a
decline in  production.  For the three months ended  September 30, 2001,  22,788
barrels of oil,  10,478  barrels  of NGLs and  44,376  mcf of gas were sold,  or
40,662 BOEs.  For the three months ended  September 30, 2000,  25,000 barrels of
oil, 11,842 barrels of NGLs and 46,163 mcf of gas were sold, or 44,536 BOEs. Due
to the decline  characteristics  of the  Partnership's  oil and gas  properties,
management expects a certain amount of decline in production in the future until
the Partnership's economically recoverable reserves are fully depleted.

The average  price  received per barrel of oil  decreased  $4.26,  or 14%,  from
$30.54 for the three  months  ended  September  30,  2000 to $26.28 for the same
period in 2001. The average price  received per barrel of NGLs decreased  $4.53,
or 28%, from $15.94  during the three months ended  September 30, 2000 to $11.41
for the same period in 2001. The average price received per mcf of gas decreased
32% from $3.17 during the three months ended September 30, 2000 to $2.16 for the
same period in 2001.

A gain on  disposition of assets of $11,959  recognized  during the three months
ended September 30, 2001 was due to $10,791 salvage income from one well plugged
and abandoned in the current period and $1,168 from equipment  credits  received
on one fully  depleted  well.  Abandoned  property  costs of $213 were  incurred
during the three months ended September 30, 2001 to plug this well.

Costs and Expenses:

Total costs and  expenses  increased  to  $594,508  for the three  months  ended
September  30,  2001 as compared  to  $473,930  for the same period in 2000,  an
increase of $120,578,  or 25%.  This increase was due to increases in production
costs,  the  impairment  of oil  and gas  properties,  depletion  and  abandoned
property costs, offset by a decline in G&A.

Production costs were $456,072 for the three months ended September 30, 2001 and
$368,259 for the same period in 2000 resulting in an $87,813  increase,  or 24%.
The  increase  was  primarily  due to higher  ad  valorem  taxes and  additional
workover  and well  maintenance  costs  incurred to stimulate  well  production,
offset by a decrease in production taxes.

During this period,  G&A  decreased  41% from $37,886 for the three months ended
September  30, 2000 to $22,471 for the same period in 2001,  primarily  due to a
lower percentage of the managing general partner's G&A being allocated  (limited
to 3% of oil and gas revenues) as a result of decreased oil and gas revenues.

The Partnership recognized a non-cash impairment provision of $30,575 related to
its proved oil and gas properties for the three months ended September 30, 2001.


                                       10






Depletion was $85,177 for the three months ended  September 30, 2001 as compared
to $67,785 for the same period in 2000,  representing an increase of $17,392, or
26%. This increase was attributable to a reduction in proved reserves during the
period  ended  September  30,  2001 as a result  of lower  commodity  prices  as
compared to the same period in 2000,  offset by a reduction in the Partnership's
net depletable  basis from charges taken in accordance  with SFAS 121 during the
fourth  quarter of 2000 and by a decrease in oil production of 2,212 barrels for
the three  months  ended  September  30,  2001 as compared to the same period in
2000.

Liquidity and Capital Resources

Net Cash Provided by Operating Activities

Net cash provided by operating  activities  increased  $135,819  during the nine
months ended  September 30, 2001 from the same period ended  September 30, 2000.
This increase was due to  reductions of $314,558 in working  capital and $12,392
in G&A  expenses,  offset by  increases  in  production  costs of  $101,111  and
abandoned  property  costs of $8,509 and a decline in oil and gas sales receipts
of $81,511.  The decrease in oil and gas receipts  resulted  from the decline in
oil and NGL prices  during 2001 which  resulted in a $90,026  decline to oil and
gas receipts and $192,845  resulting from the decline in production  during 2001
as  compared  to the same  period in 2000,  offset by an  increase in gas prices
which contributed an additional  $201,360 to oil and gas receipts.  The increase
in production  costs was primarily due to higher ad valorem taxes and additional
workover and well maintenance  costs incurred to stimulate well production.  The
decrease in G&A was primarily due to a lower  percentage of the managing general
partner's  G&A being  allocated  (limited  to 3% of oil and gas  revenues)  as a
result of decreased oil and gas revenues.

Net Cash Provided by (Used in) Investing Activities

The  Partnership's  investing  activities during the nine months ended September
30, 2001 and 2000 included expenditures related to equipment upgrades on various
oil and gas properties.

Proceeds from asset  dispositions of $20,552 and $5,487 were  recognized  during
the nine months ended  September 30, 2001 and 2000,  respectively.  The proceeds
recognized  during the period ended  September  30, 2001 were  primarily  due to
salvage  income from one well plugged and abandoned  during the current  period.
The proceeds  recognized during the period ended September 30, 2000 were derived
from the sale of equipment on one fully depleted well.

Net Cash Used in Financing Activities

For the nine months ended September 30, 2001, cash distributions to the partners
were  $1,436,366,  of which  $14,364 was  distributed  to the  managing  general
partner and  $1,422,002  to the  limited  partners.  For the same  period  ended
September 30, 2000, cash distributions to the partners were $1,619,198, of which
$16,192 was  distributed to the managing  general  partner and $1,603,006 to the
limited partners.

During  2001,  the  Partnership  made  distributions  in  March  and July but no
distributions  were made by the Partnership during September pending the vote of

                                       11





the proposed merger of the Partnership into Pioneer Natural  Resources USA, Inc.
("Pioneer USA"). For further information, see "Proposal to acquire partnerships"
below.

Proposal to acquire partnerships

On October 22,  2001,  Pioneer  Natural  Resources  Company  ("Pioneer")  mailed
definitive materials (the "proxy  statement/prospectus") to solicit the approval
of limited partners of 46 Parker & Parsley limited  partnerships,  including the
Partnership,  of an agreement and plan of merger among  Pioneer,  Pioneer USA, a
wholly-owned subsidiary of Pioneer, and those limited partnerships.  The special
meetings of the limited partners to consider and vote on the merger proposal are
scheduled  for  December  20,  2001.  The record  date to  identify  the limited
partners who are  entitled to notice of and to vote at the special  meetings was
September  21, 2001.  Each  partnership  that approves the agreement and plan of
merger and the other related  merger  proposals will merge with and into Pioneer
USA.  As a result,  the  partnership  interests  of those  partnerships  will be
converted into the right to receive Pioneer common stock.

The proxy  statement/prospectus  is  non-binding  and is subject to, among other
things,  consideration  of offers from third parties to purchase any partnership
or its assets and the majority approval of the limited partnership  interests in
each partnership.

A copy of the proxy  statement/prospectus  may be obtained  without  charge upon
request from Pioneer Natural Resources Company, 5205 North O'Connor Blvd., Suite
1400, Irving, Texas 75039, Attention: Investor Relations.

The limited partners are urged to read the proxy statement/prospectus of Pioneer
filed with the Securities and Exchange  Commission because it contains important
information about the proposed mergers,  including  information about the direct
and indirect  interests  of Pioneer USA and Pioneer in the mergers.  The limited
partners may also obtain the final proxy statement/prospectus and other relevant
documents  relating to the  proposed  mergers free through the internet web site
that the Securities and Exchange Commission maintains at www.sec.gov.

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

(1)    "Item 2. Management's Discussion and Analysis of Financial Condition and
       Results of Operations" contains forward looking statements that involve
       risks and uncertainties. Accordingly, no assurances can be given that the
       actual events and results will not be materially different than the
       anticipated results described in the forward looking statements.

                           Part II. Other Information

Item 6.     Exhibits and Reports on Form 8-K

(a)    Exhibits

(b)    Reports on Form 8-K - none


                                       12




                           PARKER & PARSLEY 90-B, L.P.
                        (A Delaware Limited Partnership)



                               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 thereunto duly authorized.


                                           PARKER & PARSLEY 90-B, L.P.

                                    By:    Pioneer Natural Resources USA, Inc.,
                                             Managing General Partner




Dated:  November 7, 2001           By:    /s/ Rich Dealy
                                           ----------------------------------
                                           Rich Dealy, Vice President and
                                             Chief Accounting Officer



                                       13