As filed with the Securities and Exchange Commission on January 18, 2000
                                                      Registration No. _________

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                    --------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                    --------

                                 CITIGROUP INC.
             (Exact Name of Registrant as Specified in Its Charter)

          Delaware                                    52-1568099
(State or Other Jurisdiction                       (I.R.S. Employer
of Incorporation or Organization)                 Identification No.)
                                    --------

        153 East 53rd Street                             10043
            New York, NY                               (Zip Code)
(Address of Principal Executive Offices)


                       Citicorp 1988 Stock Incentive Plan
                       Citicorp 1997 Stock Incentive Plan
                 Citicorp Executive Incentive Compensation Plan
                       Citigroup 2000 Stock Purchase Plan
                    Travelers Group Capital Accumulation Plan
                            (Full Title of the Plan)


                               Stephanie B. Mudick
                         General Counsel - Corporate Law
                                 Citigroup Inc.
                              153 East 53rd Street
                               New York, NY 10043
                    (Name and Address of Agent For Service)

                                 (212) 559-1000
                       (Telephone Number, Including Area
                           Code, of Agent For Service)


                                    ---------

<TABLE>

                         CALCULATION OF REGISTRATION FEE

<CAPTION>

Title Of Securities To       Amount To Be         Proposed Maximum        Proposed Maximum           Amount Of
     Be Registered            Registered         Offering Price Per      Aggregate Offering      Registration Fee
                                                        Share                   Price
------------------------ ---------------------- ---------------------- ------------------------ --------------------
<S>                          <C>                      <C>                <C>                       <C>

Common Stock, $.01 par
value per share              50,000,000 shares        $53.46875 (1)      $2,673,437,500            $705,787.50 (1)

------------------------ ---------------------- ---------------------- ------------------------ --------------------
<FN>

(1)   The  registration  fee for  the  securities  registered  hereby  has  been
      calculated  pursuant to Rule 457(h) under the  Securities Act and is based
      upon the average  high and low sale price of the Common  Stock as reported
      in the consolidated reporting system on January 10, 2000.
</FN>
</TABLE>


<PAGE>

                                EXPLANATORY NOTE

      Citigroup Inc., ("Citigroup"), hereby files this Registration Statement on
Form S-8  relating  to  50,000,000  shares of common  stock,  $.01 par value per
share, of Citigroup  ("Common Stock") issuable pursuant to the provisions of the
Citicorp 1988 Stock  Incentive Plan, the Citicorp 1997 Stock Incentive Plan, the
Citicorp  Executive  Incentive  Compensation  Plan,  the  Citigroup  2000  Stock
Purchase Plan and the Travelers Group Capital Accumulation Plan.


<PAGE>

                                     PART II


               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.

The  following   documents  are  hereby   incorporated   by  reference  in  this
Registration Statement:

      (a) The Annual  Report on Form 10-K, as amended,  filed by Citigroup  Inc.
(the "Registrant") for the fiscal year ended December 31, 1998.

      (b) All other  reports  filed by  Registrant  pursuant to Section 13(a) or
15(d) of the Securities Exchange Act of 1934 (the "Exchange Act"), since the end
of the fiscal year covered by the annual report referred to in (a) above.

      (c) The  description  of the  Registrant's  Common Stock  contained in the
Registrant's  registration statement filed under the Exchange Act, as updated by
the  description  of the  Registrant's  Common Stock  contained in the Company's
Registration Statement on Form S-4 dated June 11, 1998 (File No. 333-56589), and
any  amendment  or  report  filed  for the  purpose  of  further  updating  such
description.

      All documents  subsequently  filed by the  Registrant  pursuant to Section
13(a),  13(c),  14 and  15(d) of the  Exchange  Act,  prior to the  filing  of a
post-effective amendment which indicates that all securities offered hereby have
been sold or which  deregisters all securities then remaining  unsold,  shall be
deemed to be incorporated  by reference  herein and to be a part hereof from the
date of the filing of such documents.

Item 4.  Description of Securities.

         Not applicable.

Item 5.  Interests of Named Experts and Counsel.

         Not applicable.

Item 6.  Indemnification of Directors and Officers.

      Subsection (a) of Section 145 of the General  Corporation Law of the State
of Delaware (the "DGCL")  empowers a corporation to indemnify any person who was
or is a party or is threatened to be made a party to any threatened,  pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative  (other than an action by or in the right of the  corporation)  by
reason of the fact that the person is or was a  director,  officer,  employee or
agent of the corporation, or is or was serving at the request of the corporation
as a director,  officer, employee or agent of another corporation,  partnership,
joint venture, trust or other enterprise, against expenses (including attorneys'
fees),  judgments,  fines and amounts paid in settlement actually and reasonably
incurred by the person in connection with such action, suit or proceeding if the
person acted in good faith and in a manner the person reasonably  believed to be
in or not opposed to the best interests of the


<PAGE>

corporation,  and,  with respect to any criminal  action or  proceeding,  had no
reasonable cause to believe the person's conduct was unlawful.

      Subsection  (b) of  Section  145 of the DGCL  empowers  a  corporation  to
indemnify  any person who was or is a party or is  threatened to be made a party
to any  threatened,  pending or  completed  action or suit by or in right of the
corporation  to procure a judgment  in its favor by reason of the fact that such
person  acted  in  any of the  capacities  set  forth  above,  against  expenses
(including  attorneys'  fees) actually and reasonably  incurred by the person in
connection  with the defense or  settlement of such action or suit if the person
acted in good  faith  and in a manner  he  reasonably  believed  to be in or not
opposed to the best interests of the corporation, except that no indemnification
may be made in  respect of any  claim,  issue or matter as to which such  person
shall have been adjudged to be liable to the corporation  unless and only to the
extent  that the Court of Chancery or the court in which such action or suit was
brought shall  determine upon  application  that,  despite the  adjudication  of
liability  but in view of all the  circumstances  of the  case,  such  person is
fairly and reasonably entitled to indemnity for such expenses which the Court of
Chancery or such other court shall deem proper.

      Section 145 of the DGCL further  provides that to the extent a director or
officer of a  corporation  has been  successful  on the merits or  otherwise  in
defense of any action, suit or proceeding referred to in subsections (a) and (b)
of Section 145, or in defense of any claim, issue or matter therein, such person
shall be indemnified against expenses  (including  attorneys' fees) actually and
reasonably incurred by such person in connection therewith; that indemnification
provided for by Section 145 shall not be deemed exclusive of any other rights to
which the indemnified party may be entitled;  that indemnification  provided for
by Section 145 shall,  unless  otherwise  provided when  authorized or ratified,
continue as to such person who has ceased to be a director, officer, employee or
agent and shall  inure to the  benefit of such  person's  heirs,  executors  and
administrators;  and empowers the corporation to purchase and maintain insurance
on behalf of a director  or officer of the  corporation  against  any  liability
asserted  against such person and incurred by such person in any such  capacity,
or arising out of such person's  status as such,  whether or not the corporation
would have the power to indemnify  such person  against such  liabilities  under
Section 145.  Section Four of Article IV of the  Registrant's  By-Laws  provides
that the  Registrant  shall  indemnify its directors and officers to the fullest
extent permitted by the DGCL.

      The  Registrant  also provides  liability  insurance for its directors and
officers  which  provides  for  coverage  against  loss from claims made against
directors and officers in their capacity as such, including,  subject to certain
exceptions, liabilities under the federal securities laws.

      Section 102(b)(7) of the DGCL provides that a certificate of incorporation
may contain a provision  eliminating  or limiting  the  personal  liability of a
director to the corporation or its  stockholders for monetary damages for breach
of fiduciary duty as a director provided that such provision shall not eliminate
or limit the liability of a director (i) for any breach of the  director's  duty
of loyalty to the  corporation or its  stockholders,  (ii) for acts or omissions
not in good faith or which involve intentional misconduct or a knowing violation
of law,  (iii) under Section 174 of the DGCL, or (iv) for any  transaction  from
which the director derived an improper  personal  benefit.  Article TENTH of the
Registrant's  Restated  Certificate  of  Incorporation  limits the  liability of
directors to the fullest extent permitted by Section 102(b)(7).

Item 7.  Exemption from Registration Claimed.

         Not applicable.


<PAGE>


Item 8.  Exhibits.

         See Exhibit Index attached hereto.

Item 9.  Undertakings.

      (a) The undersigned registrant hereby undertakes:

      (1) To file,  during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:

            (i) To include any  prospectus  required by Section  10(a)(3) of the
      Securities Act of 1933;

            (ii) To reflect in the  prospectus any facts or events arising after
      the  effective  date of the  registration  statement  (or the most  recent
      post-effective amendment thereof) which, individually or in the aggregate,
      represent  a  fundamental  change  in the  information  set  forth  in the
      registration  statement.  Notwithstanding  the foregoing,  any increase or
      decrease in volume of  securities  offered (if the total  dollar  value of
      securities  offered  would not exceed that which was  registered)  and any
      deviation from the low or high end of the estimated maximum offering range
      may be  reflected  in the form of  prospectus  filed  with the  Commission
      pursuant  to Rule 424(b) if, in the  aggregate,  the changes in volume and
      price  represent no more than 20 percent  change in the maximum  aggregate
      offering price set forth in the "Calculation of Registration Fee" table in
      the effective registration statement;

            (iii) To include any material  information  with respect to the plan
      of distribution not previously disclosed in the registration  statement or
      any material  change to such  information in the  registration  statement;
      provided,  however,  that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply
      if the  registration  statement is on Form S-3,  Form S-8 or Form F-3, and
      the information  required to be included in a post-effective  amendment by
      those  paragraphs is contained in periodic reports filed with or furnished
      to the  Securities and Exchange  Commission by the registrant  pursuant to
      Section 13 or Section  15(d) of the  Securities  Exchange Act of 1934 that
      are incorporated by reference in the registration statement.

      (2)  That,  for  the  purpose  of  determining  any  liability  under  the
Securities Act of 1933, each such post-effective amendment shall be deemed to be
a new registration statement relating to the securities offered therein, and the
offering of such  securities at that time shall be deemed to be the initial bona
fide offering thereof.

      (3) To remove from registration by means of a post-effective amendment any
of the securities being registered which remain unsold at the termination of the
offering.

      (b) The undersigned  registrant  hereby  undertakes  that, for purposes of
determining  any liability  under the Securities Act of 1933, each filing of the
registrant's  annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (and, where applicable,  each filing of an employee benefit
plan's annual report pursuant to Section 15(d) of the Securities Exchange Act of
1934) that is incorporated by reference in the  registration  statement shall be
deemed to be a new  registration  statement  relating to the securities  offered
therein,  and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.


<PAGE>

      (c)  Insofar  as  indemnification   for  liabilities   arising  under  the
Securities Act of 1933 may be permitted to directors,  officers and  controlling
persons of the registrant  pursuant to the foregoing  provisions,  or otherwise,
the  registrant  has been  advised  that in the  opinion of the  Securities  and
Exchange  Commission such  indemnification is against public policy as expressed
in the Act and is,  therefore,  unenforceable.  In the  event  that a claim  for
indemnification  against  such  liabilities  (other  than  the  payment  by  the
registrant of expenses  incurred or paid by a director,  officer or  controlling
person of the  registrant  in the  successful  defense  of any  action,  suit or
proceeding)  is  asserted by such  director,  officer or  controlling  person in
connection with the securities being registered,  the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit  to a  court  of  appropriate  jurisdiction  the  question  whether  such
indemnification  by it is against public policy as expressed in the Act and will
be governed by the final adjudication of such issue.


<PAGE>

                                   SIGNATURES

      Pursuant to the  requirements  of the  Securities Act of 1933, as amended,
Citigroup Inc. certifies that it has reasonable grounds to believe that it meets
all of the requirements for filing this  Registration  Statement on Form S-8 and
has duly caused this  Registration  Statement  to be signed on its behalf by the
undersigned,  thereunto duly  authorized,  in The City of New York, State of New
York, this 18th day of January, 2000.



                                              CITIGROUP INC.
                                              (Registrant)

                                              By /s/ Heidi G. Miller
                                                 -------------------
                                                 Heidi G. Miller
                                                 Chief Financial Officer

      Pursuant to the  requirements  of the  Securities Act of 1933, as amended,
this  Registration  Statement on Form S-8 or  amendment thereto  has been signed
below by the  following persons in the capacities  indicated on this 18th day of
January, 2000.


             Signature                                  Capacity
             ---------                                  --------

                                            Chairman of the Board, Co-Chief
         /s/ John S. Reed                   Executive Officer (Principal
         ----------------------             Executive Officer) and Director
         John S. Reed
                                            Chairman of the Board, Co-Chief
         /s/ Sanford I. Weill               Executive Officer (Principal
         ----------------------             Executive Officer) and Director
         Sanford I. Weill


         /s/ Heidi G. Miller                Chief Financial Officer
         ----------------------             (Principal Financial Officer)
         Heidi G. Miller

                                            Chief Accounting Officer
         /s/ Irwin Ettinger                 and Chief Tax Officer
         ----------------------             (Principal Accounting Officer)
         Irwin Ettinger


         /s/ Roger W. Trupin
         ----------------------             Controller
         Roger W. Trupin                    (Principal Accounting Officer)

                  *
         ----------------------             Director
         C. Michael Armstrong


<PAGE>


                  *
         ----------------------             Director
         Alain J. P. Belda


                  *
         ----------------------             Director
         Kenneth J. Bialkin


                  *
         ----------------------             Director
         Kenneth T. Derr


                  *
         ----------------------             Director
         John M. Deutch


                  *
         ----------------------             Director
         Ann Dibble Jordan


                  *
         ----------------------             Director
         Reuben Mark


                  *
         ----------------------             Director
         Michael T. Masin


                  *
         ----------------------             Director
         Dudley C. Mecum


                  *
         ----------------------             Director
         Richard D. Parsons


                  *
         ----------------------             Director
         Andrall E. Pearson


<PAGE>



         ----------------------             Director
         Robert E. Rubin


                  *
         ----------------------             Director
         Robert B. Shapiro


                  *
         ----------------------             Director
         Franklin A. Thomas



         ----------------------             Director
         Edgar S. Woolard


                  *
         ----------------------             Director
         Arthur Zankel



*By:   /s/ Heidi G. Miller
       -------------------------
       Heidi G. Miller, as
       Attorney-in-fact under the
       Powers of Attorney filed
       as Exhibit 24 hereto.


<PAGE>


                                 EXHIBIT INDEX

Exhibit
Number            Description of Document

5                 Opinion of Stephanie B. Mudick,
                  with respect to the legality of the securities
                  being registered

23.1              Consent of Stephanie B. Mudick
                  (included in the opinion filed as Exhibit 5)

23.2              Consent of KPMG LLP

23.3              Consent of Arthur Andersen LLP

24                Powers of Attorney of the directors of the Registrant.