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                                                                      EXHIBIT 21

                      MONTHLY CERTIFICATEHOLDERS' STATEMENT

                           Discover Card Trust 1991 D

                      -------------------------------------
                                   CREDIT CARD

                            PASS-THROUGH CERTIFICATES
                      -------------------------------------



        Under the Pooling and Servicing Agreement dated as of Oct. 1, 1991 (the
"Agreement") by and among Greenwood Trust Company (the "Servicer"), Discover
Receivables Financing Group Inc and Wilmington Trust Company, as Trustee, the
Servicer is required to prepare certain information each month regarding current
distributions to Investor Certificateholders and the performance of the Trust
during the previous month. The information which is required to be prepared with
respect to the distribution of June 16, 1997, and with respect to theperformance
of the Trust during the Due Period ended in May 31, 1997, is set forth below.
Certain of the information is presented on the basis of an original principal
amount of $1,000 per Class A Certificate. Certain other information is presented
based on the aggregate amounts for the Trust as a whole.

        Information Regarding the Current Monthly Distribution (stated on the
basis of $1,000 original principal amount).


1. The total amount of the distribution to Class A Certificate-holders on 
   June 16, 1997, per $1,000 interest ........................................
   ........................................... $                   0.000000000

2. The total amount of the distribution to Class B Certificate-holders on 
   June 16, 1997, per $1,000 interest ........................................
   ........................................... $                   0.000000000

3. The amount of the distribution set forth in paragraph 1 above in respect of 
   interest on the Class A Certificates, per $1,000 interest .................
   ........................................... $                   0.000000000

4. The amount of the distribution set forth in paragraph 2 above in respect of
   interest on the Class B Certificates, per $1,000 interest .................
   ........................................... $                   0.000000000
   2

5. The amount of the distribution set forth in paragraph 1 above in respect of
   principal on the Class A Certificates, per $1,000 interest.................
   ........................................... $                   0.000000000

6. The amount of the distribution set forth in paragraph 2 above in respect of
   principal on the Class B Certificates, per $1,000 interest.................
   ........................................... $                   0.000000000


Information Regarding the Performance of the Trust.


1. Collections of Receivables.

   (a) The aggregate amount of Finance Charge Collections processed during the
       related Due Period .................... $                  7,292,626.88

   (b) The aggregate amount of Principal Collections processed during the
       related Due Period .................... $                 77,197,030.37

   (c) The aggregate amount of Finance Charge Collections processed during the
       related Due Period which was allocated in respect of the Investor
       Certificates .......................... $                  5,925,259.34

   (d) The aggregate amount of Principal Collections processed during the
       related Due Period which was allocated in respect of the Investor
       Certificates .......................... $                 62,722,587.17

   (e) The aggregate amount of Finance Charge Collections processed during the
       related Due Period which was allocated in respect of the Class A
       Certificates .......................... $                  5,386,334.21

   (f) The aggregate amount of Principal Collections processed during the
       related Due Period which was allocated in respect of the Class A
       Certificates .......................... $                57,017,726.63

   (g) The aggregate amount of Finance Charge Collections processed during the
       related Due Period which was allocated in respect of the Class B
       Certificates .......................... $                   538,925.13

   (h) The aggregate amount of Principal Collections processed during the
       related Due Period which was allocated in respect of the Class B
       Certificates .......................... $                 5,704,860.54

   (i) The aggregate amount of Finance Charge Collections processed during the
       related Due Period which was allocated in respect of the Seller
       Certificate ........................... $                 1,367,367.54
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   (j) The aggregate amount of Principal Collections processed during the
       related Due Period which was allocated in respect of the Seller
       Certificate ........................... $                14,474,443.20


2. Principal Receivables in the Trust;  Principal Funding Account.

   (a) The aggregate amount of Principal Receivables in the Trust as of the end
       of the Due Period ended in May 31, 1997 (which reflects the Principal
       Receivables represented by the Seller Certificate and the Investor
       Certificates) ......................... $               474,134,611.60

   (b) The amount of Principal Receivables in the Trust represented by the
       Class A Certificates (the "Class A Interest") as of the Due Period Ended
       in May 31, 1997 ....................... $               350,000,000.00

   (c) The amount of Principal Receivables in the Trust represented by the
       Class B Certificates (the "Class B Interest") as of the Due Period Ended
       in May 31, 1997 ....................... $                35,000,000.00

   (d) The Class A Interest and the Class B Interest set forth in paragraph 2
       (b) and 2 (c) above as a percentage of the aggregate amount of Principal
       Receivables set forth in paragraph 2 (a) above .................. 81.20%

   (e) The Class A Interest set forth in paragraph 2 (b) above as a percentage
       of the aggregate amount of Principal Receivables set forth in paragraph 2
       (a) above .............................                           73.82%

   (f) The Class B Interest set forth in paragraph 2 (c) above as a percentage
       of the aggregate amount of Principal Receivables set forth in paragraph 2
       (a) above .............................                            7.38%

   (g) The Aggregate Invested Amount as of the end of the current Distribution
       Date .................................. $                385,000,000.00

   (h) The Invested Amount as of the end of the current Distribution Date with
       respect to the Class A Certificates ....$                350,000,000.00

   (i) The Invested Amount as of the end of the current Distribution Date with
       respect to the Class B Certificates ....$                 35,000,000.00

   (j) The total amount to be deposited into the Principal Funding Account in
       respect of Principal Collections on such Distribution Date............
       .......................................$                           0.00
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   (k) The amount of the deposit referred to in paragraph 2(j) which was
       allocated in respect of the Class A Certificates......................
       ...................................... $                           0.00

   (l) The amount of the deposit referred to in paragraph 2(j) into the
       Principal Funding Account on such Distribtion Date which was allocated in
       respect of the Class B Certificates ...$                           0.00

   (m) The total amount on deposit in the Principal Funding Account on such
       Distribution Date (after giving effect to the deposit referred to in
       paragraph 2(j) ....................... $                           0.00

   (n) The total amount on deposit in the Principal Funding Account on such
       Distribution Date for the benefit of the Class A Certificates (after
       giving effect to the deposit referred to in paragraph 2(k)
       ...................................... $                           0.00

   (o) The total amount on deposit in the Principal Funding Account on such
       Distribution Date for the benefit of the Class B Certificates (after
       giving effect to the deposit referred to in paragraph 2(l)
       ...................................... $                           0.00

   (p) The total amount of Investment Income since the last Distribution Date
       ...................................... $                           0.00

   (q) The total amount of Investment Income since the last Distribution Date in
       respect of the Class A Certificates ...$                           0.00

   (r) The total amount of Investment Income since the last Distribution Date in
       respect of the Class B Certificates ...$                           0.00

   (s) The Deficit Accumulation Amount (after giving effect to the deposit
       referred in paragraph 2(j).............$                           0.00

3. Interest Funding Account.

   (a) The total amount to be deposited into the Interest Funding Account in
       respect of Certificate Interest on such Distribution Date
       ...................................... $                   2,577,604.16

   (b) The amount of Certificate Interest to be deposited into the Interest
       Funding Account on such Distribtion Date in respect of the Class A
       Certificates ..........................$                   2,333,333.33
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   (c) The amount of Certificate Interest to be deposited into the Interest
       Funding Account on such Distribtion Date in respect of the Class B
       Certificates ..........................$                     244,270.83

   (d) The total amount on deposit in the Interest Funding Account in respect of
       Certificate Interest on such Distribution Date (after giving effect to 
       the deposit referred to in paragraph 3(a) 
       ...................................... $                   5,155,208.32

   (e) The total amount of Certificate Interest on deposit in the Interest
       Funding Account on such Distribution Date in respect of the Class A
       Certificates (after giving effect to the deposit referred to in paragraph
       3(b) ................................. $                   4,666,666.66

   (f) The total amount of Certificate Interest on deposit in the Interest
       Funding Account on such Distribution Date in respect of the Class B
       Certificates (after giving effect to the deposit referred to in paragraph
       3(c) ................................. $                     488,541.66


4. Investor Charged-Off Amount.

   (a) The aggregate amount of Receivables charged-off as uncollectible during
       the Due Period ended in May 31, 1997 allocable to the Investor
       Certificates (the "Investor Charged-Off Amount") .................. $
       1,833,608.20

   (b) The aggregate amount of Receivables charged-off as Uncollectible during
       the Due Period ended in May 31, 1997 allocable to the Class A 
       Certificates (the "Class A Charged-Off Amount") 
       ....................................... $                   1,666,834.48

   (c) The sum of (i) the aggregate amount of Receivables charged-off as
       uncollectible during the Due Period ended in May 31, 1997 allocable to 
       the Class B Certficates and (ii) the sum of (a) the positive difference,
       if any, between the Class B Subordinated Payment and Class B Finance 
       Charge Collections (less Class B Excess Servicing) and (b) the amount by 
       which the Investor Interest for the Class B Certificates is reduced 
       pursuant to subsection 4.03(c) (i)(C)(the "Class B Charged-Off Amount") 
       ....................................... $                   1,530,975.39

   (d) The Cumulative Class A Charged-Off Amount on .......... 
       ............ June 16, 1997 ............ $                           0.00

   (e) The Cumulative Class B Charged-Off Amount on ..........
       ............ June 16, 1997 ............ $                           0.00
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5. Investor losses; Reimbursement of Charge-Offs.

   (a) The amount of Class A Investor Loss, as defined in Section 4.06 (b) of
       the Agreement, during the Due Period ended in May 31, 1997 
       ....................................... $                           0.00

   (b) The amount of Class B Investor Loss, as defined in Section 4.06 (b) of
       the Agreement, during the Due Period ended in May 31, 1997 
       ....................................... $                           0.00

   (c) The amount of Class A Investor Loss set forth in Paragraph 5 (a) above,
       per $1,000 interest (which will have the effect of reducing, pro rata,
       the amount of each Class A Certficate-holder's investment)
       ........................................ $                   0.000000000

   (d) The amount of Class B Investor Loss set forth in Paragraph 5 (b) above,
       per $1,000 interest (which will have the effect of reducing, pro rata,
       the amount of each Class B Certficate- holder's investment)
       ........................................ $                   0.000000000

   (e) The total amount reimbursed to the Trust in the current month pursuant to
       Section 4.06 (c) of the Agreement, if any, in respect of Class A Investor
       Losses in prior months ................. $                          0.00

   (f) The total amount reimbursed to the Trust in the current month pursuant to
       Section 4.06 (c) of the Agreement, if any, in respect of Class B Investor
       Losses in prior months ................. $                          0.00

   (g) The amount set forth in paragraph 5 (e) above, per $1,000 interest (which
       will have the effect of increasing, pro rata, the amount of each Class A
       Certificateholder's investment) ........ $                   0.000000000

   (h) The amount set forth in paragraph 5 (f) above, per $1,000 interest (which
       will have the effect of increasing, pro rata, the amount of each Class B
       Certificateholder's investment) ........ $                  0.000000000

   (i) The aggregate amount of Class A Investor Losses in the Trust as of the
       end of the day on June 16, 1997 ........ $                          0.00

   (j) The aggregate amount of Class B Investor Losses in the Trust as of the
       end of the day on June 16, 1997 ........ $                          0.00
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   (k) The amount set forth in paragraph 5 (i) above, per $1,000 interest (which
       will have had the effect of reducing, pro rata, the amount of Class A
       Certificateholder's investment ) ........ $                   0.000000000

   (l) The amount set forth in paragraph 5 (j) above, per $1,000 interest (which
       will have had the effect of reducing, pro rata, the amount of Class B
       Certificateholder's investment ) ........ $                   0.000000000


6. Investor Servicing Fee.

   (a) The amount of the Class A Monthly Servicing Fee payable by the Trust to
       the Servicer for the month of May 31, 1997..............................
       ....................................... $                     583,303.95

   (b) The amount of the Class B Monthly Servicing Fee payable by the Trust to
       the Servicer for the month of May 31, 1997..............................
       ....................................... $                      58,361.98


7. Available Subordinated Amount.

   (a) The amount available to be applied pursuant to Sections 4.03 (c) (i) (B)
       and (C) of the Agreement as of the end of the day on June 16, 1997
       ....................................... $                  35,000,000.00


   (b) The amount set forth in paragraph 7(a) above as a percentage of the Class
       A Interest. ...........................                            10.00%


8. Available Class B Credit Enhancement Amount.

   (a) The amount available to be drawn under the Class B Credit Enhancement
       pursuant to Sections 4.03 (c) (i) (G) and (H) of the Agreement as of the
       end of the day on June 16, 1997 ........$                  26,950,000.00
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   (b) The amount set forth in paragraph 8 above as a percentage of the Class B
       Interest. ..............................                          77.00%


9. The Pool Factor.

   The Pool Factor represents the ratio of the amount of the Class A Invested
   amount as of the end of the day on June 16, 1997 to the amount of the Class A
   Invested Amount as of the Closing Date. The amount of a Class A
   Certificateholder's pro rata share of the Class A Invested Amount can be
   determined by multiplying the original denomination of the Class A
   Certificateholder's Certificate by the Pool Factor ....           1.00000000

   The Pool Factor represents the ratio of the amount of the Class B Invested
   amount as of the end of the day on June 16, 1997 to the amount of the Class B
   Invested Amount as of the Closing Date. The amount of a Class B
   Certificateholder's pro rata share of the Class B Invested Amount can be
   determined by multiplying the original denomination of the Class B
   Certificateholder's Certificate by the Pool Factor ....           1.00000000


10. The aggregate outstanding balance of Receivables that were delinquent by 30
   to 59 days as of the close of business on the last day of the Due Period
   related to such Distribution Date ..........$                   9,430,650.83


11. The aggregate outstanding balance of Receivables that were delinquent by 60
   days or more as of the close of business on the last day of the Due Period
   related to such Distribution Date ..........$                  13,907,700.33



                       Greenwood Trust Company as Servicer

                                       By: __________________________
                                       Title: Vice President, Director of
                                       Accounting and Treasurer
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                          MONTHLY SERVICER CERTIFICATE

                           DISCOVER CARD TRUST 1991 D

                       ----------------------------------
                                   CREDIT CARD

                            PASS-THROUGH CERTIFICATES
                       ----------------------------------



   The undersigned, a duly authorized representative of Greenwood Trust Company
("Greenwood"), as Servicer pursuant to the Pooling and Servicing Agreement dated
as of Oct. 1, 1991 (the "Pooling and Servicing Agreement" ) by and among
Greenwood, Discover Receivables Financing Group Inc and Wilmington Trust
Company, does hereby certify as follows:


   1. Greenwood  is Servicer  under the Pooling and
      Servicing Agreement.

   2. The undersigned is a Servicing Officer.

   3. The aggregate amount of Collections processed
      during the related Due Period was equal to .. $          84,489,657.25

   4. The  aggregate  amount of  Class A  Principal
      Collections  processed by the Servicer during
      the related Due Period is equal to .......... $          57,017,726.63

   5. The aggregate amount  of the Class A  Finance
      Charge  Collections processed by the Servicer
      during the related Due Period is equal to ... $           5,386,334.21

   6. The sum of all amounts payable to the  Class A
      Certificateholders on the current Distribution
      Date is equal to ............................ $                   0.00

   7. The  aggregate  amount of  Class B  Principal
      Collections  processed by the Servicer during
      the related Due Period is equal to .......... $           5,704,860.54

   8. The aggregate amount  of the Class B  Finance
      Charge  Collections processed by the Servicer
      during the related Due Period is equal to .. $              538,925.13

   9. The  amount  of  drawings  under  the  Class B
      Credit Enhancement required to be made on  the

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      succeeding Drawing Date pursuant to
      (a)  Section 4.03(c)(i)(G) is equal to...... $                    0.00
      (b)  Section 4.03(c)(i)(H) is equal to...... $                    0.00
      (c)  Section 4.05 is equal to............... $                    0.00

  10. The sum of all amounts payable to the Class B
      Certificateholders on the current Distribution
      Date is equal to ........................... $                    0.00

  11. The total amount to be deposited in the Principal
      Funding Account on the related Distribution Date
      is equal to ................................ $                    0.00

  12. The total amount on deposit in the Principal
      Funding Account  (after giving effect to the
      deposit referred to in Item 11 above) will be
      equal to ................................... $                    0.00

  13. The total amount to be deposited in the Interest
      Funding Account on the related Distribution Date
      is equal to ................................ $            2,577,604.16

  14. The total amount on deposit in the Interest
      Funding Account  (after giving effect to the
      deposit referred to in Item 13 above) will be
      equal to ................................... $            5,155,208.32

  15. The Invested Amount as of the end of the current
      Distribution Date .......................... $          385,000,000.00

      (a)  for the Class A Certificateholders will be
           equal to .............................. $          350,000,000.00

      (b)  for the Class B Certificateholders will be
           equal to .............................. $           35,000,000.00

  16. Attached hereto is a true copy of the statement
      required to be delivered by the Servicer on the
      date  of   this  Certificate  to  the   Trustee
      pursuant to section 5.02.


     IN  WHITNESS  WHEREOF,  the  undersigned  has  duly  executed  and
and delivered  this  certificate this day of                      June 16, 1997



                                        GREENWOOD TRUST COMPANY, as Servicer

                                        By: ______________________________
                                        Title: Vice President, Director of
                                        Accounting and Treasurer
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                       Greenwood Trust Company
                       Cash Collateral Account
                    Monthly Portfolio Status Report
                      Discover Card Trust 1991 D

           Due Period Ending:                  05/31/97

PORTFOLIO STATUS                               LOSSES & DELINQUENCIES



                                          # of Accounts            Dollars
                                                                    
Ending Total Outstanding                        629,331        481,221,140.54

Total Principal Outstanding                         n/a        474,134,611.60

Total Finance Charge Outstanding                    n/a          7,086,528.94

Aggregate Investor Interest                         n/a        385,000,000.00

Delinquencies (90 days or greater)                2,686          8,515,256.59
 % of Ending Total Outstanding                      n/a              1.769510%

Investor Net Charge Offs                            n/a          1,833,608.20
Annualized % of Investor Interest                   n/a              5.715142%

Monthly Principal Payment Rate                      n/a             16.291581%


                                                        PAYMENTS & YIELD

Principal Payments
(Allocable to Investor Interest)                                62,722,587.17

Finance Charges, Annual Fees & Late Fees
(Allocable to Investor Interest)                                 5,925,259.34

Annualized Gross Yield to Investor                                 18.468341%