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

                                  SCHEDULE 13D
                                 (Rule 13d-101)
                               (Amendment No. 18)


             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
            TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO
                                  RULE 13d-2(a)


                              The Korea Fund, Inc.
                              --------------------
                                (Name of Issuer)

                     Common Stock, par value $.01 per share
                     --------------------------------------
                         (Title of Class of Securities)

                                    500634100
                                    ---------
                                 (CUSIP Number)

                                 Barry M. Olliff
            c/o City of London Investment Management Company Limited
                     10 Eastcheap, London EC3M ILX, England
                                +44 207 711 0771
                                ----------------
       (Name, Address and Telephone Number of Person Authorized to Receive
                           Notices and Communications)

                                October 31, 2006
                                ----------------
             (Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
schedule because of Rule 13d-1(e), (f) or (g), check the following box / /.

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 or otherwise subject to the liabilities of that section of the Act but
shall be subject to all other provisions of the Act.
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                               (Page 1 of 6 Pages)

===================                                                  ===========
CUSIP NO. 500634100                    13D                           PAGE 2 of 6
===================                                                  ===========

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     1       NAME OF REPORTING PERSONS
             S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

             City of London Investment Group PLC, a company incorporated under
             the laws of England and Wales.
------------ -------------------------------------------------------------------
     2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP            (A) [_]
                                                                         (B) [_]

------------ -------------------------------------------------------------------
     3       SEC USE ONLY


------------ -------------------------------------------------------------------
     4       SOURCE OF FUNDS*

             OO
------------ -------------------------------------------------------------------
     5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
             TO ITEM 2(d) OR 2(e)
                                                                             [_]
------------ -------------------------------------------------------------------
     6       CITIZENSHIP OR PLACE OF ORGANIZATION

             England and Wales
--------------------------------------------------------------------------------
  NUMBER OF              7      SOLE VOTING POWER

   SHARES                       6,721,467
                   ------------ ------------------------------------------------
BENEFICIALLY             8      SHARED VOTING POWER

  OWNED BY                      0
                   ------------ ------------------------------------------------
    EACH                 9      SOLE DISPOSITIVE POWER

  REPORTING                     6,721,467
                   ------------ ------------------------------------------------
   PERSON               10      SHARED DISPOSITIVE POWER

    WITH                        0
------------ -------------------------------------------------------------------
    11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

             6,721,467
------------ -------------------------------------------------------------------
    12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
             SHARES
                                                                             [_]
------------ -------------------------------------------------------------------
    13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

             24.92%
------------ -------------------------------------------------------------------
    14       TYPE OF REPORTING PERSON*

             HC
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                               (Page 2 of 6 Pages)

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CUSIP NO. 500634100                    13D                           PAGE 3 of 6
===================                                                  ===========

================================================================================
     1       NAME OF REPORTING PERSONS
             S.S. OR I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS

             City of London Investment Management Company Limited, a company
             incorporated under the laws of England and Wales.
------------ -------------------------------------------------------------------
     2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP            (A) [_]
                                                                         (B) [_]

------------ -------------------------------------------------------------------
     3       SEC USE ONLY


------------ -------------------------------------------------------------------
     4       SOURCE OF FUNDS*

             WC
------------ -------------------------------------------------------------------
     5       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
             TO ITEM 2(d) OR 2(e)
                                                                             [_]
------------ -------------------------------------------------------------------
     6       CITIZENSHIP OR PLACE OF ORGANIZATION

             England and Wales
--------------------------------------------------------------------------------
  NUMBER OF              7      SOLE VOTING POWER

   SHARES                       6,721,467
                   ------------ ------------------------------------------------
BENEFICIALLY             8      SHARED VOTING POWER

  OWNED BY                      0
                   ------------ ------------------------------------------------
    EACH                 9      SOLE DISPOSITIVE POWER

  REPORTING                     6,721,467
                   ------------ ------------------------------------------------
   PERSON               10      SHARED DISPOSITIVE POWER

    WITH                        0
------------ -------------------------------------------------------------------
    11       AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

             6,721,467
------------ -------------------------------------------------------------------
    12       CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
             SHARES
                                                                             [_]
------------ -------------------------------------------------------------------
    13       PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

             24.92%
------------ -------------------------------------------------------------------
    14       TYPE OF REPORTING PERSON*

             IA
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                               (Page 3 of 6 Pages)


This Amendment No. 18 to Schedule 13D (this "Amendment No. 16") should be read
in conjunction with the Schedule 13D filed with the U.S. Securities and Exchange
Commission (the "SEC") on February 17, 2004 (the "Original Schedule 13D"), with
Amendment No. 1 to Schedule 13D filed with the SEC on March 1, 2004 ("Amendment
No. 1"), with Amendment No. 2 to Schedule 13D filed with the SEC on May 5, 2004
("Amendment No. 2"), with Amendment No. 3 to Schedule 13D filed with the SEC on
July 8, 2004 ("Amendment No. 3"), with Amendment No. 4 to Schedule 13D filed
with the SEC on August 31, 2004 ("Amendment No. 4"), with Amendment No. 5 to
Schedule 13D filed with the SEC on November 15, 2004 ("Amendment No. 5"), with
Amendment No. 6 to Schedule 13D filed with the SEC on December 23, 2004
("Amendment No. 6"), with Amendment No. 7 to Schedule 13D filed with the SEC on
May 18, 2005 ("Amendment No. 7"), with Amendment No. 8 to Schedule 13D filed
with the SEC on June 10, 2005 ("Amendment No. 8"), with Amendment No. 9 to
Schedule 13D filed with the SEC on July 5, 2005 ("Amendment No. 9"), with
Amendment No. 10 to Schedule 13D filed with the SEC on August 5, 2005
("Amendment No. 10"), with Amendment No. 11 to Schedule 13D filed with the SEC
on August 12, 2005 ("Amendment No. 11"), with Amendment No. 12 to Schedule 13D
filed with the SEC on September 14, 2005 ("Amendment No. 12"), with Amendment
No. 13 to Schedule 13D filed with the SEC on October 7, 2005 ("Amendment No.
13"), with Amendment No. 14 to Schedule 13D filed with the SEC on October 21,
2005 ("Amendment No. 14"), and with Amendment No. 15 to Schedule 13D filed with
the SEC on April 10, 2006 ("Amendment No. 15"), and with Amendment No. 16 to
Schedule 13D filed with the SEC on June 9, 2006 ("Amendment No. 16"), and with
Amendment No. 17 to Schedule 13D filed with the SEC on October 18, 2006
("Amendment No. 17"), and, together with Amendment No. 1, Amendment No. 2,
Amendment No. 3, Amendment No. 4, Amendment No. 5, Amendment No. 6, Amendment
No. 7, Amendment No. 8, Amendment No. 9. Amendment No. 10, Amendment No. 11,
Amendment No. 12, Amendment No. 13, Amendment No. 14, Amendment No. 15,
Amendment No. 16 and, Amendment No. 16 the "Amendments"), by City of London
Investment Group PLC ("City of London") and City of London Investment Management
Company Limited relating to the shares of common stock, par value $0.01 per
share (the "Shares"), of The Korea Fund, Inc., a Maryland corporation (the
"Fund"). This Amendment No. 18 amends Item 5 of the Original Schedule 13D as
amended by the Amendments. All other information in the Original Schedule 13D
and the Amendments remains in effect. All capitalized terms used herein and not
otherwise defined shall have the meanings ascribed thereto in the Original
Schedule 13D as amended by the Amendments.


ITEM 5.   INTERESTS IN SECURITIES OF THE ISSUER.

          Items 5(a) and 5(b) below are hereby amended and restated in their
          entirety and Item 5(c) is hereby amended as follows:

          (a) and (b). As of the date hereof, GEM, IEM, EWF, GFM, FREE, CEM and
          Accounts owned directly 1,341,044, 1,341,044, 402,591, 152,836,
          808,834, 945, and 2,674,173 Shares, respectively, representing
          approximately 4.97%, 4.97%, 1.49%, 0.57%, 3.00%, and

                               (Page 4 of 6 Pages)



          9.92%, respectively, of the Shares outstanding (based on the most
          recent Share information publicly disclosed by the Fund).

          As of the date hereof, CLIG, through its control of CLIM, is the
          beneficial owner of 6,721,467 Shares, representing approximately
          24.92% of the Shares outstanding (based on the most recent Share
          information publicly disclosed by the Fund).

          As of the date hereof, CLIM, through GEM, IEM, EWF, GFM, FREE, CEM and
          Accounts, is the beneficial owner 6,721,467 Shares, representing
          approximately 24.92% of the Shares outstanding (based on the most
          recent Share information publicly disclosed by the Fund).

          (c). Except as described below, no transactions in the Shares were
          effected by the Reporting Persons, or, to their knowledge, any of the
          persons identified in Item 2, in the last 60 days.

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 PORTFOLIO       TRADE DATE     TRAN TYPE    PAR VALUE / SHARES    TRADE PRICE
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ACCOUNT           10/5/2006        BUY                700             37.4500
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ACCOUNT           10/6/2006        BUY             17,600             37.5979
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ACCOUNT           10/9/2006        BUY             10,000             36.4900
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ACCOUNT          10/11/2006        BUY                700             36.5000
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ACCOUNT          10/12/2006        BUY             10,000             36.7343
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CEM              10/13/2006        BUY                 40             36.7000
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ACCOUNT          10/13/2006        BUY              3,000             36.7000
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ACCOUNT          10/16/2006        BUY              6,400             37.0016
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ACCOUNT          10/17/2006        BUY              6,800             36.9263
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ACCOUNT          10/18/2006        BUY              2,500             36.9800
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ACCOUNT          10/19/2006        BUY              7,700             36.9029
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ACCOUNT          10/20/2006        BUY             20,000             37.0940
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ACCOUNT          10/23/2006        BUY             10,000             37.0082
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ACCOUNT          10/24/2006        BUY              5,200             36.9154
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ACCOUNT          10/26/2006        BUY             14,100             38.0000
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                               (Page 5 of 6 Pages)


                                    SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify
that the information set forth in this statement is true, complete and correct.

Dated: November 8, 2006


                                        CITY OF LONDON INVESTMENT GROUP PLC


                                        /s/ Barry M. Olliff
                                        -----------------------------
                                        Name: Barry M. Olliff
                                        Title: Director


                                        CITY OF LONDON INVESTMENT
                                        MANAGEMENT COMPANY LIMITED


                                        /s/ Barry M. Olliff
                                        -----------------------------
                                        Name: Barry M. Olliff
                                        Title: Director


                               (Page 6 of 6 Pages)