As filed with the Securities and Exchange Commission on ______________, 1998

                                               Registration No. 333-

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                   ----------
                                    FORM S-8
             REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

                                   ----------

                           AMBAC FINANCIAL GROUP, INC.
             (Exact name of Registrant as specified in its charter)

    Delaware                                                   13-3621676
    (State or other jurisdiction of                         (I.R.S. Employer
    incorporation or organization)                        Identification Number)

                             One State Street Plaza
                            New York, New York 10004
                    (Address of Principal Executive Offices)

                  Ambac Financial Group, Inc. 1997 Equity Plan
       Ambac Financial Group, Inc. 1997 Non-Employee Directors Equity Plan
               Ambac Financial Group, Inc. Savings Incentive Plan
                            (Full title of the plan)

                                   ----------

                             Richard B. Gross, Esq.
              Senior Vice President, General Counsel and Secretary
                           Ambac Financial Group, Inc.
                             One State Street Plaza
                            New York, New York 10004
                     (Name and address of agent for service)

                                 (212) 208-3354
          (Telephone number, including area code, of agent for service)

                                   ----------

                         CALCULATION OF REGISTRATION FEE



==========================================================================================================================

                 Title of                        Amount        Proposed Maximum       Proposed Maximum        Amount of
             Securities to be                    to be        Offering Price Per         Aggregate          Registration
                Registered                     Registered          Share(*)            Offering Price          Fee(*)
- --------------------------------------------------------------------------------------------------------------------------

                                                                               
Common Stock, par value $0.01 per share**      5,500,000         $55.71875              $306,453,125          $90,404

Common Stock, par value $0.01 per share***      140,000          $55.71875              $  7,800,625          $ 2,302

Common Stock, par value $0.01 per share****     100,000          $55.71875              $  5,571,875          $ 1,644
==========================================================================================================================
<FN>
*    Pursuant to Rule 457(c) under the Securities Act of 1933, the maximum
     offering price per share and the registration fee relating to the Common
     Stock, par value $0.01 per share ("Common Stock") of Ambac Financial Group,
     Inc. ("Ambac"), being registered are based on the average of the high and
     low prices of the Common Stock on the New York Stock Exchange composite
     tape on May 11, 1998 and are utilized solely for the purpose of
     calculating the registration fee.

**   Shares available under the Ambac Financial Group, Inc. 1997 Equity Plan, as
     amended (the "Equity Plan"). In addition, this registration statement
     covers 871,693 shares of the Common Stock that were carried forward to the
     Equity Plan from Ambac's 1991 Stock Incentive Plan, as amended (the "1991
     Plan") and as to which Ambac paid a registration fee of $5,584 upon
     filing of its registration statement on Form S-8, No. 33-63134 (filed May
     21, 1993) relating to the 1991 Plan.

***  Shares available under the Ambac Financial Group, Inc. 1997 Non-Employee
     Directors Equity Plan, as amended (the "Directors Plan"). In addition, this
     registration statement covers 19,642 shares of Common Stock that were
     carried forward to the Directors Plan from Ambac's 1991 Non-Employee
     Directors Stock Plan, as amended (the "1991 Directors Plan") and as to
     which Ambac paid a registration fee of $107 upon filing of its registration
     statement on Form S-8, No. 33-47971 (filed May 18, 1992) relating to the
     1991 Directors Plan.

**** Shares available under the Ambac Financial Group, Inc. Savings Incentive
     Plan, as amended. In addition, pursuant to Rule 416(c) under the Securities
     Act of 1933, this Registration Statement covers an indeterminate amount of
     interests to be offered or sold pursuant to the Ambac Financial Group, Inc.
     Savings Incentive Plan.

</FN>


                                    Page 1 of
                        Exhibit Index appears on Page 10



                                        2




                                     Part I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

Item 1.  Plan Information.*

Item 2.  Registrant Information and Employee Plan Annual Information.*














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

*    Information required by Part I to be contained in the Section 10(a)
     prospectus is omitted from this Registration Statement in accordance with
     Rule 428 under the Securities Act of 1933, as amended (the "Securities
     Act"), and the "Note" to Part I of Form S-8.






                                     Part II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT


Item 3.  Incorporation of Documents by Reference.

                  The following documents filed with the Securities and Exchange
Commission (the "Commission") by Ambac are incorporated by reference in this
Registration Statement:

                  (a)      Annual Report on Form 10-K for the fiscal year ended
                           December 31, 1997.

                  (b)      Current Reports on Form 8-K dated February 7, 1998
                           and March 27, 1998.

                  (c)      (i) The description of Ambac's Common Stock set forth
                           in Ambac's registration statement on Form 8-A as
                           filed with the Commission on June 12, 1991, including
                           amendments thereto (as so amended, the "Form 8-A")
                           under the Securities Exchange Act of 1934, as amended
                           (the "Exchange Act") and (ii) the description of the
                           Common Stock set forth under the heading "Description
                           of Capital Stock" in Ambac's registration statement
                           on Form S-1 (Registration No. 33-40306) filed
                           pursuant to the Securities Act, and having an
                           effective date of July 11, 1991, including
                           amendments thereto, which description is incorporated
                           by reference in the Form 8-A.

                  All documents subsequently filed by Ambac pursuant to Section
13(a) and (c) of the Exchange Act, and any definitive proxy or information
statements filed pursuant to Section 14 of the Exchange Act in connection with
any subsequent stockholders' meeting and any reports filed pursuant to Section
15(d) of the Exchange Act prior to the filing of a post-effective amendment
which indicates that all securities offered have been sold or which deregisters
all securities that have not been sold, will be deemed to be incorporated by
reference into this Registration Statement and to be a part hereof from the date
of 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.

                  As authorized by Section 145 of the General Corporation Law of
Delaware, each director and officer of Ambac may be indemnified by Ambac against
expenses (including attorneys' fees, judgments, fines and amounts paid in
settlement) actually and reasonably incurred by such director or officer in
connection with the defense or settlement of any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative, in which he is involved by reason of the fact that he is or was a
director or officer of Ambac if he acted in good faith and in a manner that he
reasonably believed to be in or not opposed to the best interests of Ambac, 



and, with respect to any criminal action or proceeding, if he had no reasonable
cause to believe that his conduct was unlawful. In addition, Article VII of the
Amended and Restated Certificate of Incorporation of Ambac and Article IX of its
Bylaws authorize Ambac to indemnify any person entitled to be indemnified under
law. If the legal proceeding, however, is by or in the right of Ambac, the
director or officer may not be indemnified in respect of any claim, issue or
matter as to which he shall have been adjudged to be liable for negligence or
misconduct in the performance of his duty to Ambac unless a court determines
otherwise.

                  In addition, Ambac maintains a Directors' and Officers'
liability insurance policy.

                  Article VI of the Amended and Restated Certificate of
Incorporation of Ambac provides that, to the fullest extent permitted by law, no
director of Ambac will be personally liable for monetary damages to Ambac or its
stockholders for any breach of fiduciary duty as a director.


Item 7.  Exemption from Registration Claimed.

                  Not applicable.


Item 8.  Exhibits.

                  The following exhibits are filed as part of this Registration
Statement:

                  4.1      Ambac Financial Group, Inc. 1997 Equity Plan, as
                           amended through October 28, 1997. (Filed as Exhibit
                           10.03 to Ambac's Annual Report on Form 10-K for the
                           year ended December 31, 1997 and incorporated herein
                           by reference.)

                  4.2      Ambac Financial Group, Inc. 1997 Non-Employee
                           Directors Equity Plan, as amended through April 29,
                           1998.

                  4.3      Amended and Restated Certificate of Incorporation of
                           Ambac filed with the Secretary of State of the State
                           of Delaware on July 11, 1997. (Filed as Exhibit 4.05
                           to Ambac's Quarterly Report on Form 10-Q for the
                           period ended September 30, 1997 and incorporated
                           herein by reference.)

                  4.4      Bylaws of Ambac, as amended through January 28, 1998.
                           (Filed as Exhibit 3.02 to Ambac's Annual Report on
                           Form 10-K for the year ended December 31, 1997 and
                           incorporated herein by reference.)

                  5.1      Opinion of Shearman & Sterling re legality of Common
                           Stock being registered.

                  23.1     Consent of KPMG Peat Marwick LLP.

                  23.2     Consent of Shearman & Sterling (included in Exhibit
                           5.1).

                  In addition, Ambac undertakes that it will submit the Ambac
Financial Group, Inc. Savings Incentive Plan and any amendments thereto to the
Internal Revenue Service in a timely manner and will make all changes required
by the Internal Revenue Service in order to qualify such Plan under Section 401
of the Internal Revenue Code.






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;

                           (ii)     To reflect in the prospectus any facts or
                                    events arising after the effective date of
                                    this 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 this Registration
                                    Statement;

                           (ii)     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 the undertakings set forth in
                  paragraphs (i) and (ii) above do not apply if the information
                  required to be included in a post-effective amendment by those
                  paragraphs is contained in periodic reports filed by Ambac
                  pursuant to Section 13 or Section 15(d) of the Exchange Act
                  that are incorporated by reference in this Registration
                  Statement;

                  (2)      That, for the purpose of determining any liability
                           under the Securities Act 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; and

                  (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 further undertakes that, for
                  purposes of determining any liability under the Securities
                  Act, each filing of Ambac's annual report pursuant to Section
                  13(a) or 15(d) of the Exchange Act 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.

         (c)      Insofar as indemnification for liabilities arising under the
                  Securities Act may be permitted to directors, officers and
                  controlling persons of Ambac pursuant to the foregoing
                  provisions, or otherwise, Ambac has been advised that in the
                  opinion of the Commission such indemnification is against
                  public policy as expressed in the Securities Act and is,
                  therefore, unenforceable. In the event that a claim for
                  indemnification against such liabilities (other than the
                  payment by Ambac of expenses incurred or paid by a director,
                  officer or controlling person of Ambac 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, Ambac 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 Securities Act and will be
governed by the final adjudication of such issue.





                                   SIGNATURES


                  The Registrant. Pursuant to the requirements of the Securities
Act, Ambac Financial Group, Inc. certifies that it has reasonable grounds to
believe that it meets all of the requirements for filing 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, on the ___ day of May, 1998.



                                       Ambac Financial Group, Inc.





                                       By: /s/ Richard B. Gross
                                          --------------------------------
                                           Richard B. Gross
                                           Senior Vice President,
                                           General Counsel and Secretary



                  KNOW ALL MEN BY THESE PRESENTS that each person whose
signature to this Registration Statement appears below hereby constitutes and
appoints each of Phillip B. Lassiter, Frank J. Bivona and Richard B. Gross as
such person's true and lawful attorney-in-fact and agent, with full power of
substitution and resubstitution, for such person and in such person's name,
place and stead, in any and all capacities, to sign any and all amendments to
the Registration Statement, including post-effective amendments, and
registration statements fled pursuant to Rule 462 under the Securities Act of
1933, and to file the same, with all exhibits thereto, and other documents in
connection therewith, with the Securities and Exchange Commissions, and does
hereby grant unto each said attorney-in-fact and agent full power and authority
to do and perform each and every act and thing requisite and necessary to be
done in and about the premises, as fully to all intents and purposes as such
person might or could do in person, hereby ratifying and confirming all that
each said attorney-in-fact and agent, or any substitute therefor, may lawfully
do or cause to be done by virtue hereof.

                  Pursuant to the requirements of the Securities Act of 1933,
this Registration Statement has been signed below by the following persons in
the capacities indicated on the ___ day of May, 1998.


Signature                                    Title
- ---------                                    -----


/s/ Phillip B. Lassiter
- -----------------------       Chairman, President and Chief Executive Officer
  Phillip B. Lassiter         and Director (Principal Executive Officer)


/s/ Frank J. Bivona           Executive Vice President, Chief Financial Officer
- -----------------------       and Treasurer (Principal Financial and
    Frank J. Bivona           Accounting Officer)






Signature                                    Title
- ---------                                    -----


- -----------------------
  Michael A. Callen           Director


/s/ Renso L. Caporali
- -----------------------
  Renso L. Caporali           Director


/s/ Richard Dulude
- -----------------------
    Richard Dulude            Director


/s/ W. Grant Gregory
- -----------------------
   W. Grant Gregory           Director


/s/ C. Roderick O'Neil
- -----------------------
  C. Roderick O'Neil          Director








                  Ambac Financial Group, Inc. Savings Incentive Plan. Pursuant
to the requirements of the Securities Act of 1933, the trustee (or other persons
who administer the employee benefit plan) have 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, on the _____ day of May,
1998.




                              Ambac Financial Group, Inc. Savings Incentive Plan




                              By: /s/ Gregg L. Bienstock
                                 ----------------------------------------
                                  Gregg L. Bienstock
                                  Chairman, Plan Administrative Committee






                                  Exhibit Index




  Exhibit No.                   Description of Document                    Page


     4.1          Ambac Financial Group, Inc. 1997 Equity Plan, as
                  amended through October 28, 1997. (Filed as Exhibit
                  10.03 to Ambac's Annual Report on Form 10-K for the
                  year ended December 31, 1997 and incorporated herein
                  by reference.)


     4.2          Ambac Financial Group, Inc. 1997 Non-Employee
                  Directors Equity Plan, as amended through April 29,
                  1998.


     4.3          Amended and Restated Certificate of Incorporation of
                  Ambac filed with the Secretary of State of the State
                  of Delaware on July 11, 1997. (Filed as Exhibit 4.05
                  to Ambac's Quarterly Report on Form 10-Q for the
                  period ended September 30, 1997 and incorporated
                  herein by reference.)


     4.4          Bylaws of Ambac, as amended through January 28,
                  1998. (Filed as Exhibit 3.02 to Ambac's Annual
                  Report on Form 10-K for the year ended December 31,
                  1997 and incorporated herein by reference.)


     5.1          Opinion of Shearman & Sterling re legality of common
                  stock being registered.


     23.1         Consent of KPMG Peat Marwick LLP.


     23.2         Consent of Shearman & Sterling (included in Exhibit
                  5.1).