AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON MAY 20, 1994

REGISTRATION NO. 2-90224


SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549


POST-EFFECTIVE AMENDMENT NO. 9
TO
FORM S-6


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:

DEFINED ASSET FUND--
MUNICIPAL INVESTMENT TRUST FUND
CALIFORNIA INSURED SERIES--1

B. NAMES OF DEPOSITORS:

MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED
SMITH BARNEY SHEARSON INC.
PRUDENTIAL SECURITIES INCORPORATED
DEAN WITTER REYNOLDS INC.

C. COMPLETE ADDRESSES OF DEPOSITORS' PRINCIPAL EXECUTIVE OFFICES:

MERRILL LYNCH, PIERCE, FENNER & SMITH     SMITH BARNEY SHEARSON INC.
            INCORPORATED                    TWO WORLD TRADE CENTER
       UNIT INVESTMENT TRUSTS                     101ST FLOOR
        POST OFFICE BOX 9051                 NEW YORK, N.Y. 10048
     PRINCETON, N.J. 08543-9051

 PRUDENTIAL SECURITIES INCORPORATED        DEAN WITTER REYNOLDS INC.
          ONE SEAPORT PLAZA           TWO WORLD TRADE CENTER--59TH FLOOR
          199 WATER STREET                   NEW YORK, N.Y. 10048
        NEW YORK, N.Y. 10292

D. NAMES AND COMPLETE ADDRESSES OF AGENTS FOR SERVICE:

  TERESA KONCICK, ESQ.    THOMAS D. HARMAN, ESQ.     LEE B. SPENCER, JR.
      P.O. BOX 9051        388 GREENWICH STREET       ONE SEAPORT PLAZA
     PRINCETON, N.J.       NEW YORK, N.Y. 10013       199 WATER STREET
       08543-9051                                   NEW YORK, N.Y. 10292

      PHILIP BECKER
130 LIBERTY STREET--29TH
          FLOOR
  NEW YORK, N.Y. 10006
                                                         COPIES TO:
                                                   PIERRE DE SAINT PHALLE,
                                                            ESQ.
                                                    450 LEXINGTON AVENUE
                                                    NEW YORK, N.Y. 10017

The issuer hereby revokes its registration of an indefinite number of Units under the Securities Act of 1933 pursuant to Rule 24f-2.

Check box if it is proposed that this filing will become effective immediately upon filing pursuant to paragraph (b) of Rule 485. R




DEFINED ASSET FUNDS--
MUNICIPAL INVESTMENT TRUST FUND
CONTENTS OF REGISTRATION STATEMENT

This Post-Effective Amendment to the Registration Statement on Form S-6 comprises the following papers and documents:

The facing sheet of Form S-6.

The cross-reference sheet (incorporated by reference to the Cross-Reference Sheet to Post-Effective Amendment No. 4 to the Registration Statement on Form S-6 of Municipal Investment Trust Fund, One Hundred Sixty-Sixth Monthly Payment Series, 1933 Act File No. 2-70983).

The Signatures.

R-1

DEFINED ASSET FUNDS--
MUNICIPAL INVESTMENT TRUST FUND
CALIFORNIA INSURED SERIES--1

SIGNATURES

PURSUANT TO THE REQUIREMENTS OF THE SECURITIES ACT OF 1933, THE REGISTRANT, DEFINED ASSET FUNDS--MUNICIPAL INVESTMENT TRUST FUND, CALIFORNIA INSURED SERIES--1, CERTIFIES THAT IT MEETS ALL OF THE REQUIREMENTS FOR EFFECTIVENESS OF THIS REGISTRATION STATEMENT PURSUANT TO RULE 485(B) UNDER THE SECURITIES ACT OF 1933 AND HAS DULY CAUSED THIS REGISTRATION STATEMENT OR AMENDMENT TO THE REGISTRATION STATEMENT TO BE SIGNED ON ITS BEHALF BY THE UNDERSIGNED THEREUNTO DULY AUTHORIZED IN THE CITY OF NEW YORK AND STATE OF NEW YORK ON THE 20TH DAY OF
MAY, 1994.

SIGNATURES APPEAR ON PAGES R-3, R-4, R-5 AND R-6.

A majority of the members of the Board of Directors of Merrill Lynch, Pierce, Fenner & Smith Incorporated has signed this Registration Statement or Amendment to the Registration Statement pursuant to Powers of Attorney authorizing the person signing this Registration Statement or Amendment to the Registration Statement to do so on behalf of such members.

A majority of the members of the Board of Directors of Smith Barney Shearson Inc. has signed this Registration Statement or Amendment to the Registration Statement pursuant to Powers of Attorney authorizing the person signing this Registration Statement or Amendment to the Registration Statement to do so on behalf of such members.

A majority of the members of the Board of Directors of Prudential Securities Incorporated has signed this Registration Statement or Amendment to the Registration Statement pursuant to Powers of Attorney authorizing the person signing this Registration Statement or Amendment to the Registration Statement to do so on behalf of such members.

A majority of the members of the Board of Directors of Dean Witter Reynolds Inc. has signed this Registration Statement or Amendment to the Registration Statement pursuant to Powers of Attorney authorizing the person signing this Registration Statement or Amendment to the Registration Statement to do so on behalf of such members.

R-2

MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED
DEPOSITOR

By the following persons, who constitute a majority of      Powers of Attorney
  the Board of Directors of Merrill Lynch, Pierce,            have been filed
  Fenner & Smith Incorporated:                                under
                                                              Form SE and the
                                                              following 1933 Act
                                                              File
                                                              Number: 33-43466


      HERBERT M. ALLISON, JR.
      BARRY S. FREIDBERG
      EDWARD L. GOLDBERG
      STEPHEN L. HAMMERMAN
      JEROME P. KENNEY
      DAVID H. KOMANSKY
      DANIEL T. NAPOLI
      THOMAS H. PATRICK
      JOHN L. STEFFENS
      DANIEL P. TULLY
      ROGER M. VASEY
      ARTHUR H. ZEIKEL
      By ERNEST V. FABIO
       (As authorized signatory for Merrill Lynch, Pierce,
       Fenner & Smith Incorporated and
       Attorney-in-fact for the persons listed above)

R-3

PRUDENTIAL SECURITIES INCORPORATED
DEPOSITOR

By the following persons, who constitute a majority of      Powers of Attorney
  the Board of Directors of                                   have been filed
  Prudential Securities Incorporated:                         under Form SE and
                                                              the following 1933
                                                              Act File Number:
                                                              33-41631


      JAMES T. GAHAN
      ALAN D. HOGAN
      HOWARD A. KNIGHT
      GEORGE A. MURRAY
      LELAND B. PATON
      HARDWICK SIMMONS
      By RICHARD R. HOFFMANN
       (As authorized signatory for Prudential Securities

Incorporated and Attorney-in-fact for the persons listed above)

R-4

SMITH BARNEY SHEARSON INC.
DEPOSITOR

By the following persons, who constitute a majority of      Powers of Attorney
  the Executive Committee of the Board of Directors of        have been filed
  Smith Barney Shearson Inc.:                                 under Form SE and
                                                              the following 1933
                                                              Act File Number:
                                                              33-49753


      RONALD A. ARTINIAN
      STEVEN D. BLACK
      JAMES DIMON
      ROBERT DRUSKIN
      TONI ELLIOTT
      LEWIS GLUCKSMAN
      THOMAS GUBA
      JOHN B. HOFFMAN
      A. RICHARD JANIAK, JR.
      ROBERT Q. JONES
      JEFFREY LANE
      JACK H. LEHMAN III
      JOEL N. LEVY
      HOWARD D. MARSH
      WILLIAM J. MILLS II
      JOHN C. MORRIS
      A. GEORGE SAKS
      BRUCE D. SARGENT
      MELVIN B. TAUB
      JACQUES S. THERIOT
      STEPHEN J. TREADWAY
      PAUL UNDERWOOD

      By GINA LEMON
       (As authorized signatory for
       Smith Barney Shearson Inc. and
       Attorney-in-fact for the persons listed above)

R-5

DEAN WITTER REYNOLDS INC.
DEPOSITOR

By the following persons, who constitute a majority of      Powers of Attorney
  the Board of Directors of Dean Witter Reynolds Inc.:        have been filed
                                                              under Form SE and
                                                              the following 1933
                                                              Act File Number:
                                                              33-17085


      NANCY DONOVAN
      CHARLES A. FIUMEFREDDO
      JAMES F. HIGGINS
      STEPHEN R. MILLER
      PHILIP J. PURCELL
      THOMAS C. SCHNEIDER
      WILLIAM B. SMITH
      By MICHAEL D. BROWNE

(As authorized signatory for Dean Witter Reynolds Inc. and Attorney-in-fact for the persons listed above)

R-6