SECURITIES AND EXCHANGE COMMISSION
                           Washington, D.C. 20549


                                SCHEDULE 13G



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



                        Mack-Cali Realty Corporation
                              (Name of Issuer)

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


                                 554489104
                           ----------------------
                               (CUSIP Number)


                             December 31, 2001
--------------------------------------------------------------------------------
          (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 7 pages




------------------------------                     -----------------------------
CUSIP No.  554489104                 13G                     Page 2 of 7 Pages
-------------------------------                    -----------------------------


--------------------------------------------------------------------------------
     1       NAME OF REPORTING PERSON
             I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)

                     Security Capital Group Incorporated
--------------------------------------------------------------------------------
     2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                       (a) [ ]
                                                                       (b) [ ]
--------------------------------------------------------------------------------
     3       SEC USE ONLY

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

                      Maryland
--------------------------------------------------------------------------------

         NUMBER OF                 5       SOLE VOTING POWER
           SHARES
        BENEFICIALLY                       -0- Shares
          OWNED BY                ----------------------------------------------
            EACH                   6       SHARED VOTING POWER
         REPORTING
           PERSON                          4,817,330 Shares of Common Stock
            WITH                  ----------------------------------------------
                                   7       SOLE DISPOSITIVE POWER

                                           -0- Shares
                                  ----------------------------------------------
                                   8       SHARED DISPOSITIVE POWER

                                           4,817,330 Shares of Common Stock
--------------------------------------------------------------------------------

     9    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                     4,817,330 Shares of Common Stock
--------------------------------------------------------------------------------
    10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                     [ ]
--------------------------------------------------------------------------------
    11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

                         8.45% of the Shares of Common Stock
--------------------------------------------------------------------------------
    12      TYPE OF REPORTING PERSON*

                        HC
--------------------------------------------------------------------------------

                   *SEE INSTRUCTIONS BEFORE FILLING OUT!



                             Page 2 of 7 pages






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

CUSIP No.  554489104                  13G                    Page 3 of 7 Pages
-------------------------------                      ---------------------------


--------------------------------------------------------------------------------
     1       NAME OF REPORTING PERSON
             I.R.S. IDENTIFICATION NO. OF ABOVE PERSON (ENTITIES ONLY)

                 Security Capital Research & Management Incorporated
--------------------------------------------------------------------------------
     2       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                     (a) [ ]
                                                                     (b) [ ]
--------------------------------------------------------------------------------
     3       SEC USE ONLY

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

                      Delaware
--------------------------------------------------------------------------------

         NUMBER OF                 5       SOLE VOTING POWER
           SHARES
        BENEFICIALLY                       -0- Shares
          OWNED BY              ------------------------------------------------
            EACH                   6       SHARED VOTING POWER
         REPORTING
           PERSON                          4,817,330 Shares of Common Stock
            WITH                ------------------------------------------------
                                   7       SOLE DISPOSITIVE POWER

                                           -0- Shares
                                ------------------------------------------------
                                   8       SHARED DISPOSITIVE POWER

                                           4,817,330 Shares of Common Stock
--------------------------------------------------------------------------------
     9    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

                     4,817,330 Shares of Common Stock
--------------------------------------------------------------------------------
    10    CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                     (a) [ ]
                                                                     (b) [ ]
--------------------------------------------------------------------------------
    11    PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

                   8.45% of the Shares of Common Stock
--------------------------------------------------------------------------------
    12    TYPE OF REPORTING PERSON*

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

                   *SEE INSTRUCTIONS BEFORE FILLING OUT!



                             Page 3 of 7 pages



Item 1 (a).      Name of Issuer:

                 Mack-Cali Realty Corporation

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

                 11 Commerce Drive, Cranford, New Jersey 07016-3501

Item 2 (a).      Name of Person Filing:

                 Security Capital Group Incorporated, a corporation
                 organized and existing under the laws of Maryland
                 ("SCGI").

       (b).      Address of Principal Business Office or, if None, Residence:

                 125 Lincoln Avenue, Santa Fe, New Mexico 87501

       (c).      Citizenship:

                 Maryland

       (d).      Title of Class of Securities:

                 Common Stock, $.01 par value per share

       (e).      CUSIP Number:

                 554489104

Item 3. If this statement is filed pursuant to Rule 13d-1(b), or 13d-2(b) or
        (c), check whether the person filing is a:

                 (a) [ ]  Broker or dealer registered under Section 15 of the
                          Exchange Act;
                 (b) [ ]  Bank as defined in Section 3(a)(6) of the Exchange
                          Act;
                 (c) [ ]  Insurance company as defined in Section 3(a)(19) of
                          the Exchange Act;
                 (d) [ ]  Investment company registered under Section 8 of the
                          Investment Company Act;
                 (e) [ ]  An investment adviser in accordance with Rule
                          13d-1(b)(1)(ii)(E);
                 (f) [ ]  An employee benefit plan or endowment fund in
                          accordance with Rule 13d-1(b)(1)(ii)(F);
                 (g) |X|  A parent holding company or control person in
                          accordance with Rule 13d-1(b)(1)(ii)(G);
                 (h) [ ]  A savings association as defined in Section 3(b) of
                          the Federal Deposit Insurance Act;
                 (i) [ ]  A church plan that is excluded from the definition
                          of an investment company under Section 3(c)(14) of
                          the Investment Company Act;
                 (j) [ ]  Group, in accordance with Rule 13d-1(b)(1)(ii)(J).



                             Page 4 of 7 pages




Item 4.  Ownership.

       (a).      Amount Beneficially Owned:

                 SCGI beneficially owns 4,817,330 shares of Common Stock by
                 virtue of its position as the parent of Security Capital
                 Research & Management Incorporated.

       (b).      Percent of Class:

                 8.45% of the Common Stock determined in accordance with
                 the provisions of Rule 13d-1 promulgated under the Act.

       (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:

                          SCGI has shared power to vote or direct the vote
                          of 4,817,330 shares of Common Stock.

                 (iii).   Sole power to dispose or to direct the disposition
                          of:

                          None.

                 (iv).    Shared power to dispose or to direct the disposition
                          of:

                          SCGI has shared power to dispose or to direct the
                          disposition of 4,817,330 shares of Common Stock.

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.

                 Various persons have the right to receive or the power to
                 direct the receipt of dividends from, or the proceeds from
                 the sale of, the Common Stock. No one person's interest in
                 the Common Stock is more than five percent of the total
                 outstanding Common Stock.

Item 7.  Identification and Classification of the Subsidiary Which Acquired the
         Security Being Reported on By the Parent Holding Company.

                 See attached Exhibit A.

Item 8.          Identification and Classification of Members of the Group.

                 Not applicable.


                             Page 5 of 7 pages




Item 9.          Notice of Dissolution of a 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.


                                 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: February 13, 2002


                                          SECURITY CAPITAL GROUP INCORPORATED




                                          By: /s/ David T. Novick
                                             -----------------------------------
                                          Name:    David T. Novick
                                          Title:   Senior Vice President



                             Page 6 of 7 pages




                                 EXHIBIT A


         Pursuant to the instructions in Item 7 of this Schedule 13G, the
identity and the Item 3 classification of the relevant subsidiary are:
Security Capital Research & Management Incorporated, 11 S. LaSalle Street,
2nd Floor, Chicago, Illinois 60603, an indirect wholly-owned subsidiary of
Security Capital Group Incorporated and a registered investment adviser
under Section 203 of the Investment Advisers Act of 1940.



                             Page 7 of 7 pages