SCHEDULE 13G

                                (Rule 13d-102)

 Information to be Included in Statements Filed Pursuant to Rule 13d-1(b), (c)
         and (d) and Amendments Thereto Filed Pursuant to Rule 13d-2.

                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549


                   Under the Securities Exchange Act of 1934
                         (Amendment No. ____________)*


                             NewMarket Corporation
--------------------------------------------------------------------------------
                               (Name of Issuer)

                                 Common Stock
--------------------------------------------------------------------------------
                        (Title of Class of Securities)

                                   651587107
                    --------------------------------------
                                (CUSIP Number)

                               December 31, 2005
            -------------------------------------------------------
            (Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule
                                   is filed:

                              [X]  Rule 13d-1(b)
                              [ ]  Rule 13d-1(c)
                              [ ]  Rule 13d-1(d)

   *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 the disclosures provided in a prior cover page.

   The information required in 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 ("Act") or otherwise subject to the liabilities of that section of
the Act but shall be subject to all other provisions of the Act (however, see
the Notes).

                                 Page 1 of 12



CUSIP No. 651587107                 13G                     Page 2 of 12 Pages

-------------------------------------------------------------------------------
 1  NAME OF REPORTING PERSON/
    I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

          Artisan Partners Limited Partnership

-------------------------------------------------------------------------------
 2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
    (See Instructions)
                                                                        (a) [ ]
          Not Applicable                                                (b) [ ]

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

-------------------------------------------------------------------------------
 4  CITIZENSHIP OR PLACE OF ORGANIZATION

          Delaware

-------------------------------------------------------------------------------
              5  SOLE VOTING POWER

                     None
 NUMBER OF
   SHARES    ------------------------------------------------------------------
BENEFICIALLY  6  SHARED VOTING POWER
  OWNED BY
    EACH             1,021,900
 REPORTING
   PERSON    ------------------------------------------------------------------
    WITH      7  SOLE DISPOSITIVE POWER

                     None

             ------------------------------------------------------------------
              8  SHARED DISPOSITIVE POWER

                     1,021,900

-------------------------------------------------------------------------------
 9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

          1,021,900

-------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
    (See Instructions)

          Not Applicable

-------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

          6.0%

-------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON
    (See Instructions)

          IA
-------------------------------------------------------------------------------

                                 Page 2 of 12



CUSIP No. 651587107                 13G                     Page 3 of 12 Pages

-------------------------------------------------------------------------------
 1  NAME OF REPORTING PERSON
    S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

          Artisan Investment Corporation

-------------------------------------------------------------------------------
 2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
    (See Instructions)
                                                                        (a) [ ]
          Not Applicable                                                (b) [ ]

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

-------------------------------------------------------------------------------
 4  CITIZENSHIP OR PLACE OF ORGANIZATION

          Wisconsin

-------------------------------------------------------------------------------
              5  SOLE VOTING POWER

                     None
 NUMBER OF
   SHARES    ------------------------------------------------------------------
BENEFICIALLY  6  SHARED VOTING POWER
  OWNED BY
    EACH             1,021,900
 REPORTING
   PERSON    ------------------------------------------------------------------
    WITH      7  SOLE DISPOSITIVE POWER

                     None

             ------------------------------------------------------------------
              8  SHARED DISPOSITIVE POWER

                     1,021,900

-------------------------------------------------------------------------------
 9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

          1,021,900

-------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
    (See Instructions)

          Not Applicable

-------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

          6.0%

-------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON
    (See Instructions)

          CO

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


                                 Page 3 of 12



CUSIP No. 651587107                 13G                     Page 4 of 12 Pages

-------------------------------------------------------------------------------
 1  NAME OF REPORTING PERSON
    S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

          Andrew A. Ziegler

-------------------------------------------------------------------------------
 2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
    (See Instructions)
                                                                        (a) [ ]
          Not Applicable                                                (b) [ ]

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

-------------------------------------------------------------------------------
 4  CITIZENSHIP OR PLACE OF ORGANIZATION

          U.S.A.

-------------------------------------------------------------------------------
              5  SOLE VOTING POWER

                     None
 NUMBER OF
   SHARES    ------------------------------------------------------------------
BENEFICIALLY  6  SHARED VOTING POWER
  OWNED BY
    EACH             1,021,900
 REPORTING
   PERSON    ------------------------------------------------------------------
    WITH      7  SOLE DISPOSITIVE POWER

                     None

             ------------------------------------------------------------------
              8  SHARED DISPOSITIVE POWER

                     1,021,900

-------------------------------------------------------------------------------
 9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

          1,021,900

-------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
    (See Instructions)

          Not Applicable

-------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

          6.0%

-------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON
    (See Instructions)

          IN

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


                                 Page 4 of 12



CUSIP No. 651587107                 13G                     Page 5 of 12 Pages

-------------------------------------------------------------------------------
 1  NAME OF REPORTING PERSON
    S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

          Carlene Murphy Ziegler

-------------------------------------------------------------------------------
 2  CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
    (See Instructions)
                                                                        (a) [ ]
          Not Applicable                                                (b) [ ]

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

-------------------------------------------------------------------------------
 4  CITIZENSHIP OR PLACE OF ORGANIZATION

          U.S.A.

-------------------------------------------------------------------------------
              5  SOLE VOTING POWER

                     None
 NUMBER OF
   SHARES    ------------------------------------------------------------------
BENEFICIALLY  6  SHARED VOTING POWER
  OWNED BY
    EACH             1,021,900
 REPORTING
   PERSON    ------------------------------------------------------------------
    WITH      7  SOLE DISPOSITIVE POWER

                     None

             ------------------------------------------------------------------
              8  SHARED DISPOSITIVE POWER

                     1,021,900

-------------------------------------------------------------------------------
 9  AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

          1,021,900

-------------------------------------------------------------------------------
10  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES
    (See Instructions)

          Not Applicable

-------------------------------------------------------------------------------
11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

          6.0%

-------------------------------------------------------------------------------
12  TYPE OF REPORTING PERSON
    (See Instructions)

          IN

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


                                 Page 5 of 12



Item 1(a)        Name of Issuer:

                       NewMarket Corporation

Item 1(b)        Address of Issuer's Principal Executive Offices:

                       330 South Fourth Street
                       Richmond, VA 23218-2189

Item 2(a)        Name of Person Filing:

                       Artisan Partners Limited Partnership ("Artisan Partners")
                       Artisan Investment Corporation, the general partner of
                           Artisan Partners ("Artisan Corp.")
                       Andrew A. Ziegler
                       Carlene Murphy Ziegler

Item 2(b)        Address of Principal Business Office:

                       Artisan Partners, Artisan Corp., Mr. Ziegler and
                       Ms. Ziegler are all located at:

                       875 East Wisconsin Avenue, Suite 800
                       Milwaukee, WI 53202

Item 2(c)        Citizenship:

                       Artisan Partners is a Delaware limited partnership
                       Artisan Corp. is a Wisconsin corporation
                       Mr. Ziegler and Ms. Ziegler are U.S. citizens

Item 2(d)        Title of Class of Securities:

                       Common Stock

Item 2(e)        CUSIP Number:

                       651587107

Item 3           Type of Person:

                       (e) Artisan Partners is an investment adviser registered
                       under section 203 of the Investment Advisers Act of
                       1940; Artisan Corp. is the General Partner of Artisan
                       Partners; Mr. Ziegler and Ms. Ziegler are the principal
                       stockholders of Artisan Corp.

                                 Page 6 of 12



Item 4           Ownership (at December 31, 2005):

                       (a)  Amount owned "beneficially" within the meaning of
                            rule 13d-3:

                            1,021,900

                       (b)  Percent of class:

                            6.0% (based on 17,066,059 shares outstanding as of
                            October 31, 2005)

                       (c)  Number of shares as to which such person has:

                            (i)  sole power to vote or to direct the vote: None

                            (ii) shared power to vote or to direct the vote:
                                 1,021,900

                            (iii)sole power to dispose or to direct the
                                 disposition of: None

                            (iv) shared power to dispose or to direct
                                 disposition of: 1,021,900

Item 5           Ownership of Five Percent or Less of a Class:

                        Not Applicable

Item 6           Ownership of More than Five Percent on Behalf of Another
                 Person:

                        The shares reported herein have been acquired on behalf
                        of discretionary clients of Artisan Partners. Persons
                        other than Artisan Partners are entitled to receive all
                        dividends from, and proceeds from the sale of, those
                        shares. None of those persons, to the knowledge of
                        Artisan Partners, Artisan Corp., Mr. Ziegler or
                        Ms. Ziegler, has an economic interest in more than 5%
                        of the class.

Item 7           Identification and Classification of the Subsidiary Which
                 Acquired the Security Being Reported on by the Parent Holding
                 Company or Control Person:

                        Not Applicable

Item 8           Identification and Classification of Members of the Group:

                        Not Applicable

Item 9           Notice of Dissolution of Group:

                        Not Applicable

Item 10          Certification:

                        By signing below I certify that, to the best of my
                        knowledge and belief, the securities referred to above
                        were acquired and are held in the ordinary course of
                        business and were not acquired and are not held for the
                        purpose of or with the effect of changing or
                        influencing the control of the issuer of the securities
                        and were not acquired and are not held in connection
                        with or as a participant in any transaction having that
                        purpose or effect.

                                 Page 7 of 12



                                   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.

Date: January 27, 2006


                ARTISAN INVESTMENT CORPORATION
                for itself and as general partner of
                ARTISAN PARTNERS LIMITED PARTNERSHIP


                By: Lawrence A. Totsky*
                    ------------------------------------------------------------


                ANDREW A. ZIEGLER

                Andrew A. Ziegler*
                ----------------------------------------------------------------


                CARLENE MURPHY ZIEGLER

                Carlene Murphy Ziegler*
                ----------------------------------------------------------------


                *By: /s/ Lawrence A. Totsky
                     -----------------------------------------------------------
                     Lawrence A. Totsky
                     Chief Financial Officer of Artisan Investment Corporation
                     Attorney-in-Fact for Andrew A. Ziegler
                     Attorney-in-Fact for Carlene Murphy Ziegler

                                 Page 8 of 12



                                 Exhibit Index

Exhibit 1     Joint Filing Agreement dated as of January 27, 2006 by and among
              Artisan Partners Limited Partnership, Artisan Investment
              Corporation, Andrew A. Ziegler, and Carlene Murphy Ziegler

Exhibit 2     Power of Attorney of Andrew A. Ziegler dated as of April 2, 2002

Exhibit 3     Power of Attorney of Carlene M. Ziegler dated as of April 2, 2002

                                 Page 9 of 12



                                                                      EXHIBIT 1

                            JOINT FILING AGREEMENT

   The undersigned hereby agree to the joint filing of the Schedule 13G to
which this Agreement is attached.

   Dated: January 27, 2006



                ARTISAN INVESTMENT CORPORATION
                for itself and as general partner of
                ARTISAN PARTNERS LIMITED PARTNERSHIP


                By: Lawrence A. Totsky*
                    ------------------------------------------------------------


                ANDREW A. ZIEGLER

                Andrew A. Ziegler*
                ----------------------------------------------------------------


                CARLENE MURPHY ZIEGLER

                Carlene Murphy Ziegler*
                ----------------------------------------------------------------


                *By: /s/ Lawrence A. Totsky
                     -----------------------------------------------------------
                     Lawrence A. Totsky
                     Chief Financial Officer of Artisan Investment Corporation
                     Attorney-in-Fact for Andrew A. Ziegler
                     Attorney-in-Fact for Carlene Murphy Ziegler

                                 Page 10 of 12



                                                                      EXHIBIT 2

                               POWER OF ATTORNEY

   The undersigned, Andrew A. Ziegler, hereby appoints Lawrence A. Totsky,
Janet D. Olsen, and Gregory K. Ramirez, and each of them individually, his true
and lawful attorney-in-fact and agent, with full power to execute and file with
the United States Securities and Exchange Commission and any stock exchange or
similar authority, for and on his behalf in any and all capacities, any and all
reports required to be filed pursuant to Section 13 of the Securities Exchange
Act of 1934 and the rules thereunder, including but not limited to reports on
Schedule 13D or 13G, any and all amendments to such reports, with all exhibits,
and any other forms or documents as may be necessary in connection with the
filing of such reports with the United States Securities and Exchange
Commission and any stock exchange or similar authority, granting unto said
attorney full power and authority to do and perform any and all acts for and on
behalf of the undersigned which may be necessary or desirable to complete, as
fully as the undersigned might or could do in person.

   This Power of Attorney shall remain in full force and effect until revoked
by the undersigned in a signed writing delivered to the foregoing
attorneys-in-fact and agents.

   IN WITNESS WHEREOF the undersigned has caused this Power of Attorney to be
executed this 2nd day of April, 2002.


                                                  /s/ Andrew A. Ziegler
                                                  -----------------------------
                                                  Andrew A. Ziegler

STATE OF WISCONSIN )
                   ) SS.
COUNTY OF MILWAUKEE)

   I, Marie V. Glowacki, a Notary Public in and for the County of Milwaukee,
State of Wisconsin, DO HEREBY CERTIFY that Andrew A. Ziegler, who is personally
known to me to be the same person whose name is subscribed to the foregoing
instrument, appeared before me this day in person and acknowledged that he
signed and delivered the said instrument as his own free and voluntary act, for
the uses and purposes therein set forth.

   Given under my hand and notarial seal, this 2 day of April, 2002.


                                                  /s/ Marie V. Glowacki
                                                  -----------------------------
                                                  Notary Public

                                 Page 11 of 12



                                                                      EXHIBIT 3

                               POWER OF ATTORNEY

   The undersigned, Carlene Murphy Ziegler, hereby appoints Lawrence A. Totsky,
Janet D. Olsen, and Gregory K. Ramirez, and each of them individually, her true
and lawful attorney-in-fact and agent, with full power to execute and file with
the United States Securities and Exchange Commission and any stock exchange or
similar authority, for and on her behalf in any and all capacities, any and all
reports required to be filed pursuant to Section 13 of the Securities Exchange
Act of 1934 and the rules thereunder, including but not limited to reports on
Schedule 13D or 13G, any and all amendments to such reports, with all exhibits,
and any other forms or documents as may be necessary in connection with the
filing of such reports with the United States Securities and Exchange
Commission and any stock exchange or similar authority, granting unto said
attorney full power and authority to do and perform any and all acts for and on
behalf of the undersigned which may be necessary or desirable to complete, as
fully as the undersigned might or could do in person.

   This Power of Attorney shall remain in full force and effect until revoked
by the undersigned in a signed writing delivered to the foregoing
attorneys-in-fact and agents.

   IN WITNESS WHEREOF the undersigned has caused this Power of Attorney to be
executed this 2 day of April, 2002.


                                                  /s/ Carlene Murphy Ziegler
                                                  -----------------------------
                                                  Carlene Murphy Ziegler
STATE OF WISCONSIN )
                   ) SS.
COUNTY OF MILWAUKEE)

   I, Kim R. Ruffert, a Notary Public in and for the County of Milwaukee, State
of Wisconsin, DO HEREBY CERTIFY that Carlene Murphy Ziegler, who is personally
known to me to be the same person whose name is subscribed to the foregoing
instrument, appeared before me this day in person and acknowledged that she
signed and delivered the said instrument as her own free and voluntary act, for
the uses and purposes therein set forth.

   Given under my hand and notarial seal, this 2 day of April, 2002.


                                                  /s/ Kim R. Ruffert
                                                  -----------------------------
                                                  Notary Public

                                 Page 12 of 12