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


                                    FORM 10-Q


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

                  For the quarterly period ended March 31, 1998

                                       or

            /   / Transition Report Pursuant to Section 13 or 15(d)
                     of the Securities Exchange Act of 1934
                For the transition period from _______ to _______


                         Commission File No. 33-26097-08


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

               Delaware                                     75-2329284
    (State or other jurisdiction of                      (I.R.S. Employer
     incorporation or organization)                   Identification Number)

303 West Wall, Suite 101, Midland, Texas                       79701
(Address of principal executive offices)                     (Zip code)

       Registrant's Telephone Number, including area code : (915) 683-4768

                                 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 / /






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                        PARKER & PARSLEY 90-B CONV., L.P.

                                TABLE OF CONTENTS


                                                                          Page
                          Part I. Financial Information

Item 1.    Financial Statements

           Balance Sheets as of March 31, 1998 and
              December 31, 1997..........................................    3

           Statements of Operations for the three months
             ended March 31, 1998 and 1997...............................    4

           Statement of Partners' Capital for the three months
             ended March 31, 1998........................................    5

           Statements of Cash Flows for the three months
             ended March 31, 1998 and 1997...............................    6

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

Item 2.    Management's Discussion and Analysis of Financial
             Condition and Results of Operations.........................    7


                      Part II. Other Information

Item 6.    Exhibits and Reports on Form 8-K..............................   10

           27.1    Financial Data Schedule

           Signatures....................................................   11


                                        2

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

                          Part I. Financial Information

Item 1.   Financial Statements

                                 BALANCE SHEETS
                                                     March 31,     December 31,
                                                       1998            1997
                                                   -----------     -----------
                                                    (Unaudited)
                 ASSETS

Current assets:
  Cash and cash equivalents, including interest
     bearing deposits of $88,929 at March 31
     and $118,425 at December 31                   $    89,216     $   118,712
  Accounts receivable - oil and gas sales               93,683         126,770
                                                    ----------      ----------
        Total current assets                           182,899         245,482
                                                    ----------      ----------
Oil and gas properties - at cost,  based on the
  successful efforts accounting method               9,587,150       9,582,125
Accumulated depletion                               (7,152,877)     (7,100,097)
                                                    ----------      ----------
        Net oil and gas properties                   2,434,273       2,482,028
                                                    ----------      ----------
                                                   $ 2,617,172     $ 2,727,510
                                                    ==========      ==========
LIABILITIES AND PARTNERS' CAPITAL

Current liabilities:
  Accounts payable - affiliate                     $    33,844     $    34,538

Partners' capital:
  Managing general partner                              25,833          26,929
  Limited partners (11,897 interests)                2,557,495       2,666,043
                                                    ----------      ----------
                                                     2,583,328       2,692,972
                                                    ----------      ----------
                                                   $ 2,617,172     $ 2,727,510
                                                    ==========      ==========


  The financial information included as of March 31, 1998 has been prepared by
           management without audit by independent public accountants.

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

                                        3

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

                            STATEMENTS OF OPERATIONS
                                   (Unaudited)



                                                     Three months ended
                                                          March 31,
                                                  ------------------------
                                                     1998          1997
                                                  ----------    ----------
Revenues:
  Oil and gas                                     $  207,043    $  325,204
  Interest                                             1,917         2,192
  Gain on disposition of assets                          123           -
                                                   ---------     ---------
                                                     209,083       327,396
                                                   ---------     ---------
Costs and expenses:
  Oil and gas production                             139,603       127,127
  General and administrative                           6,995        10,632
  Depletion                                           52,780        61,895
                                                   ---------     ---------
                                                     199,378       199,654
                                                   ---------     ---------
Net income                                        $    9,705    $  127,742
                                                   =========     =========
Allocation of net income:
  Managing general partner                        $       97    $    1,277
                                                   =========     =========
  Limited partners                                $    9,608    $  126,465
                                                   =========     =========
Net income per limited partnership interest       $      .81    $    10.63
                                                   =========     =========
Distributions per limited partnership interest    $     9.93    $    19.32
                                                   =========     =========


         The financial information included herein has been prepared by
           management without audit by independent public accountants.

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

                                        4

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

                         STATEMENT OF PARTNERS' CAPITAL
                                   (Unaudited)





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

Balance at January 1, 1998            $   26,929     $2,666,043     $2,692,972

     Distributions                        (1,193)      (118,156)      (119,349)

     Net income                               97          9,608          9,705
                                       ---------      ---------      ---------

Balance at March 31, 1998             $   25,833     $2,557,495     $2,583,328
                                       =========      =========      =========











         The financial information included herein has been prepared by
           management without audit by independent public accountants.

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

                                        5

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

                            STATEMENTS OF CASH FLOWS
                                   (Unaudited)



                                                          Three months ended
                                                                March 31,
                                                       ------------------------
                                                          1998           1997
                                                       ----------    ----------
Cash flows from operating activities:
   Net income                                          $    9,705    $  127,742
   Adjustments to reconcile net income to net
     cash provided by operating activities:
       Depletion                                           52,780        61,895
       Gain on disposition of assets                         (123)          -
   Changes in assets and liabilities:
       Accounts receivable                                 33,087        70,806
       Accounts payable                                      (694)        2,195
                                                        ---------     ---------
           Net cash provided by operating activities       94,755       262,638
                                                        ---------     ---------
Cash flows from investing activities:
   Additions to oil and gas properties                     (5,025)       (4,747)
   Proceeds from asset dispositions                           123           -
                                                        ---------     ---------
           Net cash used in investing activities           (4,902)       (4,747)
                                                        ---------     ---------
Cash flows used in financing activities:
   Cash distributions to partners                        (119,349)     (232,201)
                                                        ---------     ---------
Net increase (decrease) in cash and cash equivalents      (29,496)       25,690
Cash and cash equivalents at beginning of period          118,712       123,797
                                                        ---------     ---------
Cash and cash equivalents at end of period             $   89,216    $  149,487
                                                        =========     =========



         The financial information included herein has been prepared by
           management without audit by independent public accountants.

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

                                        6

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

                          NOTES TO FINANCIAL STATEMENTS
                                 March 31, 1998
                                   (Unaudited)

Note 1.     Organization and nature of operations

Parker & Parsley 90-B Conv., L.P. (the "Partnership") was organized as a general
partnership  in 1990 under the laws of the State of Texas and was converted to a
Delaware limited partnership on August 1, 1991.

The Partnership  engages  primarily 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 as of March 31,
1998 of the Partnership  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.  However,  these interim results are not
necessarily indicative of results for a full year.

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,  1997,  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, 1400 Williams Square West, Irving, Texas 75039-3746.

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

Results of Operations

Revenues:

The Partnership's  oil and gas revenues  decreased 36% to $207,043 from $325,204
for the three months ended March 31, 1998 and 1997,  respectively.  The decrease
in revenues  resulted from lower average prices received,  offset by an increase
in production. For the three months ended March 31, 1998, 10,469 barrels of oil,
3,681  barrels of natural gas liquids  ("NGLs") and 18,363 mcf of gas were sold,
or 17,211 barrel of oil equivalents  ("BOEs").  For the three months ended March
31, 1997, 11,217 barrels of oil and 29,910 mcf of gas were sold, or 16,202 BOEs.

As of September 30, 1997, the Partnership began accounting for processed natural
gas   production  as  processed   natural  gas  liquids  and  dry  residue  gas.
Consequently,  separate product volumes will not be comparable for periods prior
to September 30, 1997.  Also,  prices for gas products will not be comparable as
the price per mcf for natural gas for the three  months  ended March 31, 1998 is
the price received for dry residue gas and the price per mcf for natural gas for
the three months ended March 31, 1997 is a price for wet gas (i.e.,  natural gas
liquids combined with dry residue gas).
                                        7

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The average  price  received per barrel of oil  decreased  $7.23,  or 33%,  from
$21.97 for the three  months  ended March 31, 1997 to $14.74 for the same period
in 1998.  The average price  received per barrel of NGLs during the three months
ended  March 31,  1998 was $6.85.  The  average  price  received  per mcf of gas
decreased  43% from $2.63  during the three months ended March 31, 1997 to $1.50
for the same period in 1998. 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 three months ended March 31, 1998.

During  most of 1997,  the  Partnership  benefitted  from  higher  oil prices as
compared to previous  years.  However,  during the fourth  quarter of 1997,  oil
prices began a downward  trend that has continued  into March 1998. On April 23,
1998, the market price for West Texas  intermediate crude was $13.80 per barrel.
A continuation of the oil price environment experienced during the first quarter
of 1998 will have an adverse effect on the Partnership's  revenues and operating
cash flow and could result in additional  decreases in the carrying value of the
Partnership's oil and gas properties.

A gain on  disposition  of assets of $123 was  received  during the three months
ended March 31, 1998 from the sale of equipment on one  saltwater  disposal well
plugged and abandoned in a prior year.

Costs and Expenses:

Total costs and expenses  decreased to $199,378 for the three months ended March
31,  1998 as compared  to  $199,654  for the same period in 1997,  a decrease of
$276.   The  decrease  was  due  to  declines  in  depletion   and  general  and
administrative expenses ("G&A"), offset by an increase in production costs.

Production  costs were  $139,603  for the three  months ended March 31, 1998 and
$127,127 for the same period in 1997,  resulting in a $12,476 increase,  or 10%.
The increase was due to additional well maintenance  costs and workover expenses
incurred  in an effort to  stimulate  well  production,  offset by a decline  in
production taxes.

G&A's  components are independent  accounting and engineering  fees and managing
general  partner  personnel  and  operating  costs.   During  this  period,  G&A
decreased,  in aggregate,  34% from $10,632 for the three months ended March 31,
1997 to $6,995 for the same period in 1998.

Depletion  was $52,780  for the three  months  ended March 31, 1998  compared to
$61,895 for the same period in 1997. This represented a decrease in depletion of
$9,115,  or 15%. This decrease was primarily  attributable to a reduction in the
Partnership's  net  depletable  basis  from  charges  taken 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") during the fourth quarter of 1997 and a reduction in oil production
of 748 barrels for the period  ended March 31, 1998  compared to the same period
in 1997, offset by a decline in oil reserves during the three months ended March
31, 1998 as a result of lower commodity prices.

                                        8

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Liquidity and Capital Resources

Net Cash Provided by Operating Activities

Net cash provided by operating  activities  decreased  $167,883 during the three
months ended March 31, 1998 from the same period in 1997. This decrease resulted
from a decrease in oil and gas sales  receipts  and an  increase  in  production
costs paid, offset by a decline in G&A expenses paid.

Net Cash Used in Investing Activities

The  Partnership's  principal  investing  activities  for the three months ended
March 31, 1998 and 1997 were related to  expenditures  for oil and gas equipment
on active properties.

Proceeds from asset  dispositions  of $123 were received during the three months
ended March 31, 1998 from the sale of equipment on one  saltwater  disposal well
abandoned in a prior year.

Net Cash Used in Financing Activities

Cash  was  sufficient  for the  three  months  ended  March  31,  1998 to  cover
distributions to the partners of $119,349 of which $1,193 was distributed to the
managing  general  partner and  $118,156 to the limited  partners.  For the same
period  ended March 31,  1997,  cash was  sufficient  for  distributions  to the
partners of $232,201 of which $2,322 was  distributed  to the  managing  general
partner and $229,879 to the limited partners.

It is expected  that future net cash  provided by operating  activities  will be
sufficient for any capital expenditures and any distributions. As the production
from the properties declines, distributions are also expected to decrease.

Information systems for the year 2000

The managing general partner will be required to modify its information  systems
in order to  accurately  process  Partnership  data  referencing  the year 2000.
Because of the importance of occurrence  dates in the oil and gas industry,  the
consequences of not pursuing these  modifications  could be very  significant to
the Partnership's ability to manage and report operating activities.  Currently,
the managing general partner plans to contract with third parties to perform the
software  programming  changes  necessary to correct any existing  deficiencies.
Such programming  changes are anticipated to be completed and tested by March 1,
1999. The managing  general  partner will allocate a portion of the costs of the
year 2000 programming  charges to the Partnership when they are incurred,  along
with recurring general and administrative  expenses.  Although the costs are not
estimable at this time, they should not be significant to the Partnership.
---------------
(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.

                                        9

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                           Part II. Other Information


Item 6.     Exhibits and Reports on Form 8-K

(a)      Exhibits

         27.1   Financial Data Schedule

(b)      Reports on Form 8-K

        (1)  On April 2, 1998,  the  Partnership  filed a Current Report on Form
             8-K dated  March 31,  1998,  reporting  under  Item 4  (Changes  in
             Registrant's  Certifying  Accountants)  the  engagement  of Ernst &
             Young  LLP  as  the  Partnership's  independent  auditors  and  the
             dismissal of KPMG Peat Marwick LLP effective upon the completion of
             the audit of the  Partnership  for the fiscal year ending  December
             31, 1997.



                                       10

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                        PARKER & PARSLEY 90-B CONV., 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 CONV., L.P.


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



Dated:  May 5, 1998                 By:      /s/ Rich Dealy
                                             --------------------------------
                                             Rich Dealy, Vice President
                                               and Chief Accounting Officer



                                       11

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