AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON APRIL 28, 2010

                                                    1933 ACT FILE NO. 333-163774
                                                   1940 ACT FILE NO. 811 - 03763

================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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

                            REGISTRATION STATEMENT ON
                                    FORM S-6
                                 AMENDMENT NO. 1

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

                FOR REGISTRATION UNDER THE SECURITIES ACT OF 1933
                     OF SECURITIES OF UNIT INVESTMENT TRUSTS
                            REGISTERED ON FORM N-8B-2

     A.   EXACT NAME OF TRUST: CLAYMORE SECURITIES DEFINED PORTFOLIOS,
          SERIES 660

     B.   NAME OF DEPOSITOR: CLAYMORE SECURITIES, INC.

     C.   COMPLETE ADDRESS OF DEPOSITOR'S PRINCIPAL EXECUTIVE OFFICES:

                            Claymore Securities, Inc.
                            2455 Corporate West Drive
                              Lisle, Illinois 60532

     D.   NAME AND COMPLETE ADDRESS OF AGENT FOR SERVICE:

Copies to:

    KEVIN ROBINSON, ESQ.                         ERIC F. FESS
    Senior Managing Director, General            Chapman and Cutler LLP
    Counsel and Secretary                        111 West Monroe Street
    Claymore Securities, Inc.                    Chicago, Illinois 60603
    2455 Corporate West Drive                    (312) 845-3000
    Lisle, Illinois  60532
    (630) 505-3736


It is proposed that this filing will become effective (check appropriate box)

/ /      immediately upon filing pursuant to paragraph (b)

/ /      on (date) pursuant to paragraph (b)

/ /      60 days after filing pursuant to paragraph (a)

/ /      on (date) pursuant to paragraph (a) of rule 485 or 486

/ /      This post-effective amendment designates a new effective date for a
         previously filed post-effective amendment.

     E.   TITLE OF SECURITIES BEING REGISTERED: Units of fractional undivided
          beneficial interest.

     F.   APPROXIMATE DATE OF PROPOSED SALE TO PUBLIC: As soon as practicable
          after the effective date of the Registration Statement.

/ /      Check box if it is proposed that this filing will become effective on
         (date) at (time) pursuant to Rule 487.

================================================================================

The registration hereby amends this Registration Statement on such date or dates
as may be necessary to delay its effective date until the registrant shall file
a further amendment which specifically states that this Registration Statement
shall thereafter become effective in accordance with Section 8(a) of the
Securities Act of 1933 or until the Registration Statement shall become
effective on such date as the Commission, acting pursuant to said Section 8(a)
may determine.

                   PRELIMINARY PROSPECTUS DATED APRIL 28, 2010

               CLAYMORE SECURITIES DEFINED PORTFOLIOS, SERIES 660

            Guggenheim ABC High Dividend Strategy Portfolio, Series 2
               (the "Guggenheim ABC High Dividend Strategy Trust")

        Guggenheim BMAC Commodity Producers Strategy Portfolio, Series 2
           (the "Guggenheim BMAC Commodity Producers Strategy Trust")


                            (A Unit Investment Trust)

     The above-referenced series is comprised of the Guggenheim ABC High
Dividend Strategy Portfolio, Series 2 and Guggenheim BMAC Commodity Producers
Strategy Portfolio, Series 2 (each, a "trust" and together, the "trusts").

     The attached final prospectus for the prior series of each respective trust
is hereby used as the preliminary prospectus for the above-referenced Series.
The narrative information and structure of the attached final prospectus will be
substantially similar to that of the final prospectus for each trust in this
Series. Information with respect to pricing, the number of units, dates and
summary information regarding the characteristics of securities to be deposited
in this Series is not available as of this date and will be different because
each series has a unique portfolio. Accordingly, the information contained
herein with regard to the previous series of each trust should be considered as
being included for informational purposes only. Ratings of the securities in
this Series are expected to be comparable to those of the securities deposited
in the previous series of each trust.

     The registration statement relating to the units of this Series is not
complete, may be changed and is not yet effective. Information contained herein
is subject to completion or amendment. The units of this Series may neither be
sold nor may an offer to buy such units be accepted prior to the time the
registration statement becomes effective. This prospectus shall neither
constitute an offer to sell nor be considered a solicitation of an offer to buy
the units. There shall be no sale of the units in any state in which such offer,
solicitation or sale would be unlawful prior to registration or qualification
under the securities laws of any such state.

     For purposes of the Guggenheim ABC High Dividend Strategy Trust and
Guggenheim BMAC Commodity Producers Strategy Trust, incorporated herein by
reference are portions of the final prospectus for Series 679 (Registration No.
333-164995) as filed on March 5, 2010, which portions shall be used as the
preliminary prospectus for such Guggenheim ABC High Dividend Strategy Trust and
Guggenheim BMAC Commodity Producers Strategy Trust.



                       CONTENTS OF REGISTRATION STATEMENT

     A.   Bonding Arrangements of Depositor:

     The Depositor has obtained the following Securities Dealer Blanket Bond for
its officers, directors and employees:

                    INSURER/POLICY NO.                        AMOUNT

               National Union Fire Insurance
            Company of Pittsburgh, Pennsylvania             $4,000,000
                          5692790

     This Registration Statement comprises the following papers and documents.

                  The Facing Sheet
                  The Prospectus
                  The Signatures
                  Consents of Counsel

     The following exhibits:

     1.1  Reference Trust Agreement (to be supplied by amendment).

   1.1.1  Standard Terms and Conditions of Trust (Reference is made to Exhibit
          1.1.1 to Amendment No. 2 to the Registration Statement on Form S-6 for
          Claymore Securities Defined Portfolios, Series 116 (File No. 333-72828
          filed on December 18, 2001).

     2.1  Code of Ethics (Reference is made to Exhibit 2.1 to the Registration
          Statement on Form S-6 for Claymore Securities Deferred Portfolios,
          Series 213 (File No. 333-122184 filed on February 9, 2005).

     3.1  Opinion of counsel as to legality of the securities being registered
          including a consent to the use of its name in the Registration
          Statement (to be supplied by amendment).

     3.2  Opinion of counsel as to Federal Income tax status of the securities
          being registered including a consent to the use of its name in the
          Registration Statement (to be supplied by amendment).

     3.3  Opinion of counsel as to New York Income tax status of the securities
          being registered including a consent to the use of its name in the
          Registration Statement (to be supplied by amendment).

     3.4  Opinion of counsel as to the Trustee and the Trust(s) including a
          consent to the use of its name in the Registration Statement (to be
          supplied by amendment).

     4.1  Consent of Independent Registered Public Accounting Firm (to be
          supplied by amendment).



                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the Registrant,
Claymore Securities Defined Portfolios, Series 660 has duly caused this
Amendment No. 1 to the Registration Statement to be signed on its behalf by the
undersigned thereunto duly authorized, in the City of Lisle, and State of
Illinois, on the 28th day of April, 2010.

                              CLAYMORE SECURITIES DEFINED PORTFOLIOS, SERIES 660
                                                                      Registrant

                                                   By: CLAYMORE SECURITIES, INC.
                                                                       Depositor

                                                          By: /s/ Kevin Robinson
                                                          ----------------------
                                                                  Kevin Robinson

     Pursuant to the requirements of the Securities Act of 1933, this Amendment
No. 1 to the Registration Statement has been signed below on April 28, 2010 by
the following persons, who constitute a majority of the Board of Directors of
Claymore Securities, Inc.




     SIGNATURE*                           TITLE**                               DATE
                                                                           

                                                                            )    By:    /s/ Kevin Robinson
                                                                                        ------------------
                                                                            )           Kevin Robinson
                                                                            )           Attorney-in-Fact*
                                                                            )
DAVID HOOTEN*                             Chief Executive Officer and       )           April 28, 2010
                                          Chairman of the Board of          )
                                          Directors                         )

MICHAEL RIGERT*                           Vice Chairman                     )           April 28, 2010

ANTHONY DILEONARDI*                       Vice Chairman                     )           April 28, 2010

BRUCE ALBELDA*                            Chief Financial Officer and                   April 28, 2010
                                          Director
/s/ Kevin Robinson
    KEVIN ROBINSON                        Senior Managing Director,                     April 28, 2010
                                          General Counsel and Secretary


- ---------------
*    An executed copy of the related power of attorney was filed as Exhibit 6.0
     to Registration Statement No. 333-149523 on April 9, 2008.

**   The titles of the persons named herein represent their capacity in and
     relationship to Claymore Securities, Inc., the Depositor.



            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

     The consent of Grant Thornton LLP to the use of its report and to the
reference to such firm in the Prospectus included in the Registration Statement
will be filed as Exhibit 4.1 to the Registration Statement.

                        CONSENT OF CHAPMAN AND CUTLER LLP

     The consent of Chapman and Cutler LLP to the use of its name in the
Prospectus included in the Registration Statement will be contained in its
opinions to be filed as Exhibits 3.1 and 3.2 to the Registration Statement.

                         CONSENT OF DORSEY & WHITNEY LLP

     The consent of Dorsey & Whitney LLP to the use of its name in the
Prospectus included in the Registration Statement will be contained in its
opinions to be filed as Exhibits 3.3 and 3.4 to the Registration Statement.

                                   MEMORANDUM

             Re: Claymore Securities Defined Portfolios, Series 660

     The list of securities comprising the trust of the fund, the evaluation,
record and distribution dates and other changes pertaining specifically to the
new series, such as size and number of units of the trust in the fund and the
statement of financial condition of the new fund will be filed by amendment.

                                    1940 ACT

                              FORMS N-8A AND N-8B-2

     Form N-8A and Form N-8B-2 were filed in respect of Claymore Securities
Defined Portfolios, Series 118 (and subsequent series) (File No. 333-81826).

                                    1933 ACT

                                  THE INDENTURE

     The form of the proposed Standard Terms and Conditions of Trust is expected
to be in all respects consistent with the form of the Standard Terms and
Conditions of Trust dated February 6, 2002 relative to Claymore Securities
Defined Portfolios, Series 118.

                                                          CHAPMAN AND CUTLER LLP

Chicago, Illinois
April 28, 2010