SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                   FORM 10-K/A
                                 Amendment No.1


(Mark One)

/     x / ANNUAL  REPORT  PURSUANT  TO  SECTION  13 OR  15(d) OF THE  SECURITIES
      EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 1999 or

/   / TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE
      SECURITIES EXCHANGE ACT OF 1934


      Commission File No.:   333-65481-25

  Norwest Asset Securities Corporation
  Mortgage Pass-Through Certificates, Series 1999-21 Trust
  (Exact name of registrant as specified in its charter)



New York                          52-2207754
(State or other jurisdiction     (I.R.S. Employer
of incorporation or              Identification  No.)
organization)


c/o Wells Fargo Bank Minnesota, N.A.
11000 Broken Land Parkway
Columbia, Maryland                            21044
(Address of principal executive offices)     (ZIP Code)


Registrant's telephone number, including area code:
     (410) 884-2000

Securities to be registered pursuant to Section 12(b) of the Act:

     NONE

Securities to be registered pursuant to Section 12(g) of the Act:

     NONE

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 ___


This Amendment No. 1 on Form 10-K/A amends Item 14 of the original Annual Report
on Form 10-K (the  "Original  Form 10-K") filed on March 24, 2000,  on behalf of
Norwest Asset Securities  Corporation Mortgage Pass-Through  Certificates Series
1999-21  established  pursuant  to the  Pooling and  Servicing  Agreement  among
Norwest Asset Securities Corporation as Seller, Wells Fargo Bank Minnesota, N.A.
as Master Servicer, United States Trust Company of New York as Trustee, and
First Union National Bank, as Trust Administrator, pursuant to which the Norwest
Asset  Securities  Corporation  Mortgage  Pass-Through  Certificates Series
1999-21  Trust   registered  under  the  Securities  Act  of  1933  (the
"Certificates") were issued.


Item 14 of the original Form 10K is amended in its entirety to read as follows:

Item 14.  Exhibits, Financial Statement Schedules, and Reports
          on Form 8-K.

          (a) Exhibits

              (99.1) Annual   Independent    Accountants'    Servicing   Reports
                     concerning servicing activities for the year ended December
                     31, 1999.

                     a)   BANK UNITED <F1>
                     b)   BANKNORTH <F1>
                     c)   FIRST UNION MTG CORP <F1>
                     d)   FT MTG COMPANIES <F1>
                     e)   HOMESIDE LENDING INC (FL) <F1>
                     f)   HUNTINGTON MTG CO <F1>
                     g)   MORGAN STANLEY DEAN WITTER <F1>
                     h)   SUN TRUST MTG INC <F1>

             (99.2)  Report  of  Management   as  to  Compliance   with  Minimum
                     Servicing Standards for the year ended December 31, 1999.

                     a)   BANK UNITED <F1>
                     b)   BANKNORTH <F3>
                     c)   FIRST UNION MTG CORP <F1>
                     d)   FT MTG COMPANIES <F1>
                     e)   HOMESIDE LENDING INC (FL) <F1>
                     f)   HUNTINGTON MTG CO <F1>
                     g)   MORGAN STANLEY DEAN WITTER <F1>
                     h)   SUN TRUST MTG INC <F1>


              (99.3) Annual  Statements  of  Compliance  under the  Pooling  and
                     Servicing Agreements for the year ended December 31, 1999.

                     a)   BANK UNITED <F1>
                     b)   BANKNORTH <F1>
                     c)   FIRST UNION MTG CORP <F1>
                     d)   FT MTG COMPANIES <F1>
                     e)   HOMESIDE LENDING INC (FL) <F1>
                     f)   HUNTINGTON MTG CO <F1>
                     g)   MORGAN STANLEY DEAN WITTER <F1>
                     h)   SUN TRUST MTG INC <F1>


              (99.4) Aggregate Statement of Principal and Interest Distributions
                     to Certificates Holders. <F2>


            (b)  On October 8, 1999,  November 4, 1999,  and  December 10, 1999,
                 reports  on Form 8-K  were  filed  by the  Company  in order to
                 provide the statements for the monthly distributions to holders
                 of the  Certificates.  No other  reports  on Form 8-K have been
                 filed  during the last  quarter  of the period  covered by this
                 report.

            (c) Not applicable.

            (d)  Omitted.

<F1>  Filed herewith.
<F2>  Previously filed.
<F3>  Such document is not filed  herewith  since such document was not received
      by the reporting person.


                           SIGNATURE

Pursuant to the  requirements of Section 13 or 15(d) 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:

 Norwest Asset Securities Corporation
 Mortgage Pass-Through Certificates, Series 1999-21 Trust


Signed:   Wells Fargo Bank Minnesota, N.A., as Master Servicer

By:   Sherri Sharps, Vice president
By:  /s/  Sherri Sharps, Vice president

Dated:  April 6, 2001


Exhibit Index

Exhibit No.

99.1      Annual Independent Accountants' Servicing Reports concerning servicing
          activities for the year ended December 31, 1999.

                     a)   BANK UNITED <F1>
                     b)   BANKNORTH <F1>
                     c)   FIRST UNION MTG CORP <F1>
                     d)   FT MTG COMPANIES <F1>
                     e)   HOMESIDE LENDING INC (FL) <F1>
                     f)   HUNTINGTON MTG CO <F1>
                     g)   MORGAN STANLEY DEAN WITTER <F1>
                     h)   SUN TRUST MTG INC <F1>

99.2      Report of Management as to Compliance with Minimum Servicing Standards
          for the year ended December 31, 1999.

                     a)   BANK UNITED <F1>
                     b)   BANKNORTH <F3>
                     c)   FIRST UNION MTG CORP <F1>
                     d)   FT MTG COMPANIES <F1>
                     e)   HOMESIDE LENDING INC (FL) <F1>
                     f)   HUNTINGTON MTG CO <F1>
                     g)   MORGAN STANLEY DEAN WITTER <F1>
                     h)   SUN TRUST MTG INC <F1>

99.3      Annual  Statements  of  Compliance  under the  Pooling  and  Servicing
          Agreements for the year ended December 31, 1999.

                     a)   BANK UNITED <F1>
                     b)   BANKNORTH <F1>
                     c)   FIRST UNION MTG CORP <F1>
                     d)   FT MTG COMPANIES <F1>
                     e)   HOMESIDE LENDING INC (FL) <F1>
                     f)   HUNTINGTON MTG CO <F1>
                     g)   MORGAN STANLEY DEAN WITTER <F1>
                     h)   SUN TRUST MTG INC <F1>


99.4      Aggregate Statement of Principal and Interest Distributions to
          Certificate Holders.<F2>

<F1>  Filed herewith.
<F2>  Previously filed.
<F3>  Such document is not filed  herewith  since such document was not received
      by the reporting person.