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

                                  SCHEDULE 13G

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

                          FactSet Research Systems Inc.
                      ------------------------------------
                                (Name of Issuer)

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

                                    303075105
                       -----------------------------------
                                 (CUSIP Number)

Check the following  box if a fee is being paid with this  statement [ ]. (A fee
is not required only if the filing person:  (1) has a previous statement on file
reporting  beneficial  ownership  of more  than  five  percent  of the  class of
securities  described  in Item 1;  and (2) has  filed  no  amendment  subsequent
thereto reporting  beneficial  ownership of five percent or less of such class.)
(See Rule 13d-7.)

    * 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
Notes).

               CUSIP No.303075105  Schedule 13G Page 2 of 5 Pages

- --------------------------------------------------------------------------------
   1   NAME OF REPORTING PERSON

       Howard E. Wille

- --------------------------------------------------------------------------------
   2   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
                                                     (a)  [ ]
                                                     (b)  [X]

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

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

       United States of America
- --------------------------------------------------------------------------------
                    5    SOLE VOTING POWER
 NUMBER OF SHARES        6,122,046
 BENEFICIALLY       ------------------------------------------------------------
 OWNED BY           6    SHARED VOTING POWER
 EACH                    n/a
 REPORTING          ------------------------------------------------------------
 PERSON             7    SOLE DISPOSITIVE POWER
 WITH                    6,122,046
                    ------------------------------------------------------------
                    8    SHARED DISPOSITIVE POWER
                         n/a

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

      6,122,046
- --------------------------------------------------------------------------------
  10  CHECK IF THE AGGREGATE  AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES [X]

      As  of  December 31, 2000,  Adelaide  McManus,  Mr. Wille's  spouse, owned
      324,239 shares of common  stock and  options  to  purchase  29,000  shares
      of Common Stock.   Mr. Wille  disclaims   beneficial   ownership  of  such
      shares.
- --------------------------------------------------------------------------------
  11  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

      18.6%
- --------------------------------------------------------------------------------
  12  TYPE OF REPORTING PERSON

      IN
- --------------------------------------------------------------------------------

              CUSIP No.303075105  SCHEDULE 13G Page 3 of 5 Pages

ITEM 1(A).  NAME OF ISSUER:
            FactSet Research Systems Inc.

ITEM 1(B).  ADDRESS OF ISSUER'S PRINCIPAL EXECUTIVE OFFICES:
            One Greenwich Plaza
            Greenwich, CT 06830

ITEM 2(A).  NAME OF PERSON FILING:
            Howard E. Wille

ITEM 2(B).  ADDRESS OF PRINCIPAL BUSINESS OFFICE, OR IF NONE, RESIDENCE:
            One Greenwich Plaza
            Greenwich, CT 06830

ITEM 2(C).  CITIZENSHIP:
            United States of America

ITEM 2(D).  TITLE OF CLASS OF SECURITIES:
            Common Stock

ITEM 2(E).  CUSIP NUMBER:
            303075105

ITEM 3.     IF THIS STATEMENT IS FILED PURSUANT TO RULES 13d-1(b), OR
            13(d)-2(b), CHECK WHETHER THE PERSON FILING IS A:
            n/a

              CUSIP No.303075105  SCHEDULE 13G Page 4 of 5 Pages

ITEM 4(A).  AMOUNT BENEFICIALLY OWNED:
            6,122,046

ITEM 4(B).  PERCENT OF CLASS:
            18.6%

ITEM 4(C).  NUMBER OF SHARES AS TO WHICH SUCH PERSON HAS:

              (1)   sole power to vote or to direct the vote
                    6,122,046

              (i)   shared power to vote or to direct the vote
                    n/a

              (ii)  sole power to dispose or to direct the disposition of
                    6,122,046

              (iii) shared power to dispose or to direct the disposition of
                    n/a

ITEM 5.     OWNERSHIP OF FIVE PERCENT OR LESS OF A CLASS.

            n/a

ITEM 6.     OWNERSHIP OF MORE THAN FIVE PERCENT ON BEHALF OF ANOTHER PERSON.

            n/a

ITEM 7.     IDENTIFICATION AND CLASSIFICATION OF THE SUBSIDIARY WHICH ACQUIRED
            THE SECURITY BEING REPORTED ON BY THE PARENT HOLDING COMPANY.

            n/a

               CUSIP No.303075105  SCHEDULE 13G Page 5 of 5 Pages

ITEM 8.     IDENTIFICATION AND CLASSIFICATION OF MEMBERS OF THE GROUP:
            n/a

ITEM 9.     NOTICE OF DISSOLUTION OF GROUP.
            n/a

ITEM 10.    CERTIFICATION.

            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.

                                                       February 9, 2001
                                                       -------------------------
                                                       DATE

                                                       By:/s/ Howard E. Wille
                                                       -------------------------
                                                       SIGNATURE

                                                       Howard E. Wille
                                                       Director
                                                       -------------------------
                                                       NAME AND TITLE