Executed in 100 Counterparts, No.      .

                    SUPPLEMENTAL INDENTURE

                       DATED JUNE 1, 1997

            CENTRAL ILLINOIS PUBLIC SERVICE COMPANY

                               TO

                FIRST TRUST NATIONAL ASSOCIATION
                       and F. SGARAGLINO,
                          AS TRUSTEES



  (SUPPLEMENTAL  TO  THE  INDENTURE OF MORTGAGE  OR  DEED  OF  TRUST  DATED
  OCTOBER  1, 1941, EXECUTED BY CENTRAL ILLINOIS PUBLIC SERVICE COMPANY  TO
  CONTINENTAL  ILLINOIS  NATIONAL BANK AND TRUST  COMPANY  OF  CHICAGO  AND
  EDMOND B. STOFFT, AS TRUSTEES)



              (PROVIDING FOR FIRST MORTGAGE BONDS,
         MEDIUM-TERM NOTE SERIES 1997-2, DUE 2001, 2006 and 2017)
                                     



This instrument was prepared by William J. Harmon, of
Jones, Day, Reavis & Pogue, 77 West Wacker, Suite 3500,
Chicago, Illinois 60601-1692

          THIS SUPPLEMENTAL INDENTURE, dated June 1, 1997, made and entered
into  by and between CENTRAL ILLINOIS PUBLIC SERVICE COMPANY, a corporation
organized and existing under the laws of the State of Illinois (hereinafter
commonly   referred  to  as  the  "Company"),  and  FIRST  TRUST   NATIONAL
ASSOCIATION  (formerly  First  Trust  of  Illinois,  National  Association,
successor  trustee to Bank of America Illinois, formerly Continental  Bank,
formerly  Continental  Bank, National Association and formerly  Continental
Illinois  National Bank and Trust Company of Chicago), a  national  banking
association having its office or place of business in the City of  Chicago,
Cook  County, State of Illinois (hereinafter commonly referred  to  as  the
"Trustee"),  and  F.  Sgaraglino (successor Co-Trustee),  of  the  City  of
Chicago, Cook County, State of Illinois, as Trustees under the Indenture of
Mortgage  or  Deed of Trust dated October 1, 1941, heretofore executed  and
delivered  by the Company to Continental Illinois National Bank  and  Trust
Company  of  Chicago and Edmond B. Stofft, as Trustees, as amended  by  the
Supplemental Indentures dated, respectively, September 1, 1947, January  1,
1949,  February 1, 1952, September 1, 1952, June 1, 1954, February 1, 1958,
January  1,  1959,  May 1, 1963, May 1, 1964, June 1, 1965,  May  1,  1967,
April  1, 1970, April 1, 1971, September 1, 1971, May 1, 1972, December  1,
1973,  March  1,  1974, April 1, 1975, October 1, 1976, November  1,  1976,
October  1,  1978,  August  1, 1979, February 1, 1980,  February  1,  1986,
May 15, 1992, July 1, 1992, September 15, 1992, April 1, 1993, June 1, 1995
and March 15, 1997, heretofore executed and delivered by the Company to the
Trustees under said Indenture of Mortgage or Deed of Trust dated October 1,
1941; said Indenture of Mortgage or Deed of Trust dated October 1, 1941, as
amended  by  said  Supplemental  Indentures,  being  hereinafter  sometimes
referred  to  as the "Indenture"; and said First Trust National Association
and  F.  Sgaraglino, as such Trustees, being hereinafter sometimes referred
to as the "Trustees" or the "Trustees under the Indenture"; WITNESSETH:

          WHEREAS, the Company has determined, by resolutions duly  adopted
by  its Board of Directors and/or the Executive Committee thereof, to issue
bonds of an additional series under and to be secured by the Indenture,  as
hereby amended, to be known and designated as First Mortgage Bonds, Medium-
Term Note Series 1997-2 (hereinafter sometimes referred to as the "bonds of
Series 1997-2" or the "bonds of said Series"), and the bonds of said Series
shall  be  authorized, authenticated and issued only  as  registered  bonds
without  coupons,  and to execute and deliver this supplemental  indenture,
pursuant  to  the  provisions  of Article  I,  as  amended,  Section  6  of
Article  II  and  Article  XVI  of  the  Indenture,  for  the  purpose   of
(1)  creating and authorizing not to exceed $80,000,000 aggregate principal
amount  of  bonds  of  Series 1997-2 and setting  forth  the  form,  terms,
provisions  and  characteristics thereof, and  (2)  modifying  or  amending
certain  provisions of the Indenture in the particulars and to  the  extent
hereinafter specifically provided; and

          WHEREAS,  the  execution and delivery  of  the  Company  of  this
supplemental indenture have been duly authorized by the Board of  Directors
of  the Company and/or the Executive Committee thereof; and the Company has
requested,  and hereby requests, the Trustees to enter into and  join  with
the  Company in the execution and delivery of this supplemental  indenture;
and
          WHEREAS,  the  bonds  of  Series 1997-2  are  to  be  authorized,
authenticated  and  issued  only in the form of  registered  bonds  without
coupons, and each of the bonds of Series 1997-2 and the certificate of  the
Trustee thereon shall be substantially in the following form, to wit:


                         [form of bond]


No._______                                                           $______

          Illinois Commerce Commission ID Number 5994


            CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
      First Mortgage Bond, Medium-Term Note Series 1997-2



  Original
   Issue            Dated           Maturity
    Date             Date             Date          CUSIP
  --------          -----           --------        -----

                      *                *


                   Interest                        Initial
  Interest         Payment           Record        Optional
    Rate            Dates            Dates     Redemption Date
  --------         --------          ------    ---------------

       *%           June 1           May 15
                  December 1      November 15         *

REGISTERED OWNER

PRINCIPAL AMOUNT                                    DOLLARS



  *  To be completed in accordance with the terms of Section 1 of Article I
hereof.

            Unless   this   certificate  is  presented  by  an   authorized
representative  of  The Depository Trust Company, a  New  York  corporation
("DTC"),  to  the  Company  or  its agent  for  registration  of  transfer,
exchange, or payment, and any certificate issued is registered in the  name
of  Cede  &  Co.  or  in such other name as is requested by  an  authorized
representative  of DTC (and any payment is made to Cede & Co.  or  to  such
other  entity as is requested by an authorized representative of DTC),  ANY
TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR  TO  ANY
PERSON IS WRONGFUL inasmuch as the Registered Owner hereof, Cede & Co., has
an interest herein.

           Central Illinois Public Service Company, an Illinois corporation
(hereinafter  referred  to as the "Company"), for  value  received,  hereby
promises  to  pay  to the Registered Owner specified above,  or  registered
assigns,  the  Principal  Amount  specified  above  on  the  Maturity  Date
specified  above, and to pay to the Registered Owner interest on  said  sum
from  the Dated Date hereof, at the Interest Rate specified above,  payable
half-yearly  on  the  Interest Payment Dates specified  above,  until  said
principal  sum  is  paid.  The interest so payable on any Interest  Payment
Date  will  be  paid,  subject  to  certain  exceptions  provided  in   the
Supplemental Indenture dated June 1, 1997, hereinafter referred to, to  the
Registered Owner at the close of business of the Trustee on the immediately
preceding Record Date.  Both the principal of and the interest on this bond
shall  be  payable at the office or agency of the Company in  the  City  of
Chicago, State of Illinois, in any coin or currency of the United States of
America which at the time of payment is legal tender for public and private
debts, or, at the option of the Registered Owner, in like coin or currency,
at the office or agency of the Company in the Borough of Manhattan, City of
New  York,  State of New York.  At the option of the Company,  interest  on
this  bond may be paid by check mailed on the Interest Payment Date to  the
Registered Owner.

            EXCEPT  UNDER  THE  LIMITED  CIRCUMSTANCES  DESCRIBED  IN   THE
INDENTURE, THIS GLOBAL BOND MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY THE
DEPOSITARY  OR  BY  A NOMINEE OF THE DEPOSITARY TO THE DEPOSITARY,  ANOTHER
NOMINEE  OF  THE DEPOSITARY, A SUCCESSOR OF THE DEPOSITARY OR A NOMINEE  OF
SUCH SUCCESSOR.

           This bond is one of the bonds issued and to be issued from  time
to  time  under and in accordance with and all secured by the indenture  of
mortgage or deed of trust dated October 1, 1941, executed and delivered  by
the  Company to First Trust National Association (formerly First  Trust  of
Illinois,  National  Association, successor  trustee  to  Bank  of  America
Illinois,  formerly Continental Bank, formerly Continental  Bank,  National
Association  and  formerly Continental Illinois  National  Bank  and  Trust
Company of Chicago and hereinafter referred to as the "Trustee") and Edmond
B.  Stofft,  as Trustees, and the various indentures supplemental  thereto,
including the Supplemental Indenture dated June 1, 1997 pursuant  to  which
$80,000,000  in  aggregate principal amount of the  First  Mortgage  Bonds,
Medium-Term Note Series 1997-2 are authorized, each executed and  delivered
by the Company to the Trustees under said indenture of mortgage or deed of
trust dated October 1, 1941, prior to the authentication of this bond (said
indenture  of  mortgage  or deed of trust and said supplemental  indentures
being hereinafter referred to, collectively, as the "Indenture"); and  said
First  Trust  National Association and F. Sgaraglino (successor Co-Trustee)
being now the Trustees under the Indenture.  Reference to the Indenture and
to  all supplemental indentures, if any, hereafter executed pursuant to the
Indenture  is  hereby made for a description of the property mortgaged  and
pledged,  the  nature  and extent of the security and  the  rights  of  the
holders and Registered Owners of said bonds and of the Trustees and of  the
Company  in  respect of such security.  By the terms of the  Indenture  the
bonds  to be secured thereby are issuable in series, which may vary  as  to
date,  amount,  date of maturity, rate of interest, redemption  provisions,
medium  of payment and in other respects as in the Indenture provided.   Of
the bonds of Series 1997-2, $20,000,000 mature on June 1, 2001, $20,000,000
mature on June 1, 2006 and $40,000,000 mature on June 1, 2017.  [The  bonds
of  Series 1997-2 maturing June 1, [2001] [2006], of which this is one, are
not  subject  to redemption.]*  [At the option of the Company and  upon  30
days' notice by first-class mail and with the effect provided in Article  V
of  the  Indenture, bonds of Series 1997-2 maturing June 1, 2017, of  which
this  is  one, may be redeemed on and after the Initial Optional Redemption
Date specified above, as a whole at any time, or in part from time to time,
at  the redemption price, expressed as a percentage of the principal amount
of  the bonds hereinafter stated under "Redemption Price," in effect at the
date  fixed for redemption, together with accrued interest to such date  on
the bonds to be redeemed:

     If redeemed                   If redeemed
     during the                    during the
     12 months                     12 months
     beginning      Redemption     beginning    Redemption
     June 1         Price          June 1       Price
     __________     __________     ________     __________

      (The  redemption  prices set forth in Article I of this  supplemental
indenture are incorporated in and made a part of this form of bond by
reference thereto and shall be inserted at this point in each such bond.)]**

           In case of certain events of default specified in the Indenture,
the principal of this bond may be declared or may become due and payable in
the  manner  and  with the effect provided in the Indenture.   No  recourse
shall  be had for the payment of the principal of or interest on this bond,
or  for  any claim based hereon, or otherwise in respect hereof or  of  the
Indenture  or  any  indenture  supplemental  thereto,  to  or  against  any
incorporator, stockholder, officer or director, past, present or future, of
the  Company,  or  of  any  predecessor or  successor  corporation,  either
directly or


______________________
 * Applicable only to Series 1997-2 Bonds maturing June 1, 2001 and June 1,
2006.
** Applicable only to Series 1997-2 Bonds maturing June 1, 2017.


through  the  Company, or such predecessor or successor corporation,  under
any  constitution or statute or rule of law, or by the enforcement  of  any
assessment,  penalty,  or otherwise, all such liability  of  incorporators,
stockholders,  directors  and officers being waived  and  released  by  the
Registered  Owner hereof by the acceptance of this bond and being  likewise
waived  and  released  by  the  terms  of  the  Indenture.   This  bond  is
transferable by the Registered Owner hereof, in person or by attorney  duly
authorized,  at  the principal office or place of business of  the  Trustee
under  the Indenture, upon the surrender and cancellation of this bond  and
the  payment  of any stamp tax or other governmental charge, and  upon  any
such  transfer a new registered bond or bonds without coupons, of the  same
series  and maturity and for the same aggregate principal amount,  will  be
issued  to the transferee in exchange herefore; provided, that the  Company
shall  not be required [(a) to register, transfer or exchange any bonds  of
Series  1997-2  maturing  June 1, 2017 during a  period  beginning  at  the
opening  of business on the tenth business day next preceding any selection
of  bonds of Series 1997-2 maturing June 1, 2017 to be redeemed and  ending
at  the  close  of  business on the day on which the applicable  notice  of
redemption  is given, (b) to register, transfer or exchange  any  bonds  of
Series  1997-2 maturing June 1, 2017 selected, called or being  called  for
redemption  in  whole  or  in part or ( c )]**  to  register,  transfer  or
exchange any bonds of Series 1997-2  for  a  period of ten (10) days next
preceding an Interest  Payment Date with respect to bonds of said Series.

          This bond shall not be valid or become obligatory for any purpose
unless  and until it shall have been authenticated by the execution by  the
Trustee  or  its  successor in trust under the Indenture of  the  Trustee's
Certificate endorsed hereon.

           IN  WITNESS WHEREOF, Central Illinois Public Service Company has
caused  this  bond  to be executed in its name by the manual  or  facsimile
signature of its President or one of its Vice-Presidents, and its corporate
seal or a facsimile thereof  to be affixed or imprinted hereon and attested
by  the  manual  or  facsimile signature of its Secretary  or  one  of  its
Assistant Secretaries.

                              CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
                              
                              
                              By
                                          President
ATTEST:


By
    Secretary


_____________________
** Applicable only to Series 1997-2 Bonds maturing June 1, 2017.

           This  bond is one of the bonds of the series designated therein,
described in the within mentioned Indenture.

                              FIRST TRUST NATIONAL ASSOCIATION,
                              as Trustee
                              
                              
                              
                              By
                                      Authorized Officer
                              
                     [end of form of bond]

         NOW, THEREFORE, in consideration of the premises and of the sum of
One  Dollar ($1.00) duly paid by the Trustees to the Company, and of  other
good   and   valuable  considerations,  the  receipt  whereof   is   hereby
acknowledged, and for the purpose of further assuring to the Trustees under
the  Indenture  their  title  to, or lien upon,  the  property  hereinafter
described,  under  and  pursuant to the terms of the Indenture,  as  hereby
amended,  and  for  the purpose of further securing the  due  and  punctual
payment  of the principal of and interest and the premium, if any,  on  all
bonds  which  have been heretofore or shall be hereafter issued  under  the
Indenture  and indentures supplemental thereto and which shall  be  at  any
time  outstanding thereunder and secured thereby, and for  the  purpose  of
securing  the faithful performance and observance of all the covenants  and
conditions  set forth in the Indenture and/or in any indenture supplemental
thereto,  the  Company  has given, granted, bargained,  sold,  transferred,
assigned, pledged, mortgaged, warranted the title to and conveyed,  and  by
these  presents does give, grant, bargain, sell, transfer, assign,  pledge,
mortgage,  warrant  the  title  to and convey  unto  FIRST  TRUST  NATIONAL
ASSOCIATION and F. SGARAGLINO, as Trustees under the Indenture  as  therein
provided, and their successors in the trusts thereby created, and to  their
assigns, all the right, title and interest of the Company in and to any and
all premises, plants, property, leases and leaseholds, franchises, permits,
rights and powers, of every kind and description, real and personal,  which
have   been   acquired  by  the  Company  through  construction,  purchase,
consolidation or merger, or otherwise, subsequent to January 1,  1997,  and
which  are  owned  by  the  Company at the date of  the  execution  hereof,
together with the rents, issues, products and profits therefrom, excepting,
however, and there is hereby expressly reserved and excluded from the  lien
and  effect of the Indenture and of this supplemental indenture, all right,
title  and  interest of the Company, now owned, in and  to  (a)  all  cash,
bonds, shares of stock, obligations and other securities not deposited with
the Trustee or Trustees under the Indenture, and (b) all accounts and bills
receivable,  judgments (other than for the recovery  of  real  property  or
establishing  a  lien or charge thereon or right therein)  and  chooses  in
action  not  specifically  assigned to and  pledged  with  the  Trustee  or
Trustees  under  the Indenture, and (c) all personal property  acquired  or
manufactured by the Company for sale, lease, rental or consumption  in  the
ordinary  course of business, and (d) the last day of each of  the  demised
terms created by any lease of property leased to the Company and under each
and every renewal of any  such  lease,  the last day of each and every such
demised  term  being hereby  expressly reserved to and by the Company, and
(e) all gas, oil  and other  minerals  now or hereafter existing upon,
within or under  any  real estate  of the Company subject to, or hereby
subjected to, the lien of  the Indenture.

         And upon the considerations and for the purposes aforesaid, and in
order  to provide, pursuant to the terms of the Indenture, for the issuance
under  the Indenture, as hereby amended, of bonds of Series 1997-2  and  to
fix  the terms, provisions and characteristics of the bonds of said Series,
and  to  modify or amend the Indenture in the particulars and to the extent
hereinafter  in  this  supplemental indenture  specifically  provided,  the
Company hereby covenants and agrees with the Trustees as follows:

                           ARTICLE I

          SECTION  1.   A series of bonds issuable under the Indenture,  as
hereby amended, to be known and designated as "First Mortgage Bonds, Medium-
Term Note Series 1997-2" (hereinafter in this Article sometimes referred to
as  the "bonds of Series 1997-2" or the "bonds of said Series"), and  which
shall  be executed, authenticated and issued only in the form of registered
bonds  without  coupons, is hereby created and authorized.   The  bonds  of
Series 1997-2 and the Trustee's Certificate to be endorsed thereon shall be
substantially in the form thereof hereinbefore recited.  If so directed  by
the  Company, the bonds of Series 1997-2 shall be issued as a single global
security  for  each  maturity thereof and registered in  the  name  of  The
Depository   Trust   Company  or  its  nominee   or   successor   under   a
"book-entry-only" system pursuant to a letter of representation between the
Company  and  the Trustee and said depository.  Each bond  of  said  Series
shall  be  dated as of the Interest Payment Date thereof to which  interest
was paid next preceding the date of issue, unless (a) issued on an Interest
Payment Date thereof to which interest was paid, in which event it shall be
dated  as of such issue date, or (b) issued prior to the occurrence of  the
first  Interest Payment Date thereof to which interest was paid,  in  which
event  it shall be dated the Original Issue Date specified in the  form  of
bond.   The bonds of said Series shall be due and payable in the respective
principal  amounts on the applicable Maturity Date specified  below,  shall
bear  interest  from  the  date  thereof at the  Interest  Rate  per  annum
specified below payable half-yearly on the Interest Payment Dates specified
in  the  form of bond to the Registered Owner as specified on the  registry
books  of  the  Trustee  at the close of business of  the  Trustee  on  the
applicable Record Date as provided in Section 3 of this Article I.

    Maturity Date         Principal Amount       Interest Rate
    ___________            ______________         __________

    June 1, 2001            $20,000,000              6.73%
    June 1, 2006             20,000,000              7.05%
    June 1, 2017             40,000,000              7.61%

          The bonds of Series 1997-2 shall be payable, as to both principal
and  interest,  at  the  office or agency of the Company  in  the  City  of
Chicago, State of Illinois, in any coin or currency of the United States of
America which at the time of payment is legal tender for public and private
debts, or, at the option of the Registered Owner, in like coin or currency,
at the office or agency of the Company in the Borough of Manhattan, City of
New York, State of New York.  At the option of the Company, interest on the
bonds  of Series 1997-2 may be paid by check mailed on the Interest Payment
Date  to the Registered Owner.  So long as any "book-entry-only" system  is
in effect, the bonds of said Series shall be paid as provided in the letter
of representation referred to above.

          SECTION 2.  Anything contained in Section 14 of Article I of  the
Indenture,  or elsewhere in the Indenture, to the contrary notwithstanding,
only the person in whose name any of the bonds of said Series is registered
(the  "Registered Owner") at the close of business on any Record  Date,  as
hereinafter  defined, with respect to any Interest Payment  Date  shall  be
entitled  to  receive  the interest payable on such Interest  Payment  Date
notwithstanding  the  cancellation of  such  bonds  upon  any  transfer  or
exchange  subsequent to the Record Date and prior to such Interest  Payment
Date;  provided,  however,  that if and to the  extent  the  Company  shall
default  in the payment of the interest due on such Interest Payment  Date,
such  defaulted  interest  shall be paid to  the  persons  in  whose  names
outstanding bonds of said Series are registered on the Record  Date  to  be
established by the Trustee for payment of such defaulted interest.

          SECTION 3.  The term "Record Date" as used herein with respect to
any  Interest  Payment Date (other than an Interest Payment  Date  for  the
payment  of  defaulted  interest) shall mean  the  applicable  Record  Date
specified  in  the form of bond next preceding such Interest Payment  Date,
or,  if such Record Date shall be a legal holiday or a day on which banking
institutions  in the City of Chicago, Illinois, are authorized  by  law  to
close, then the next preceding day which shall not be a legal holiday or  a
day on which such institutions are so authorized to close.

          SECTION 4.  The bonds of Series 1997-2 maturing June 1, 2001  and
June  1,  2006 are not subject to redemption.  At the option of the Company
and  upon  the  notice and in the manner and with the  effect  provided  in
Article  V  of the Indenture, except as to notice as hereinafter  provided,
bonds  of Series 1997-2 maturing June 1, 2017 may be redeemed on and  after
June  1,  2007 (the "Initial Optional Redemption Date") as a whole  at  any
time, or in part from time to time, at the redemption price, expressed as a
percentage  of the principal amount of such bonds hereinafter stated  under
"Redemption  Price,"  in effect at the date fixed for redemption,  together
with accrued interest to such date on the bonds to be redeemed:

                                              If redeemed
    If redeemed                               during the
    during the                                12 months
    12 months             Redemption          beginning         Redemption
    beginning June 1      Price               June 1            Price
    _____________         __________          __________        __________

          2007             103.81%             2010              101.52%
          2008             103.04%             2011              100.76%
          2009             102.28%             2012 (and         100.00%
                                               thereafter)

     The  foregoing redemption prices and terms shall be set forth in  each
bond  of  Series  1997-2 maturing June 1, 2017 prior to the  execution  and
authentication thereof.

          SECTION  5.   Notice of redemption of any bonds of Series  1997-2
maturing  June  1,  2017 shall be given as provided in  Article  V  of  the
Indenture; provided, however, such notice need be given only by first-class
mail and no publication of notice of redemption shall be required.

          SECTION  6.   The  Company shall not be required  (a)  to  issue,
register, transfer or exchange any bonds of Series 1997-2 maturing June  1,
2017  during  a period beginning at the opening of business  on  the  tenth
business day next preceding any selection of bonds of Series 1997-2
maturing  June 1, 2017 to be redeemed and ending at  the  close  of
business on the day on which the applicable notice of redemption is  given,
(b)  to  register, transfer or exchange any bonds of Series 1997-2 maturing
June 1, 2017 selected, called or being called for redemption in whole or in
part  or  (c) to register, transfer or exchange any bonds of Series  1997-2
for  a period of ten (10) days next preceding an Interest Payment Date with
respect to bonds of said Series.

          The bonds of said Series shall, from time to time, be executed on
behalf  of  the Company and sealed with the corporate seal of the  Company,
all  in  the manner provided or permitted by Section 6 of Article I of  the
Indenture, as follows:

          (a)  bonds of Series 1997-2 executed on behalf of the Company  by
    its  President  or  a  Vice-President and/or by  its  Secretary  or  an
    Assistant  Secretary may be so executed by the facsimile  signature  of
    such  President or Vice-President and/or of such Secretary or Assistant
    Secretary,  as  the case may be, of the Company, or of  any  person  or
    persons  who shall have been such officer or officers, as the case  may
    be,  of  the  Company on or subsequent to the date of this supplemental
    indenture, notwithstanding that he or they may have ceased to  be  such
    officer or officers of the Company at the time of the actual execution,
    authentication, issue or delivery of any of such bonds,  and  any  such
    facsimile signature or signatures of any such officer  or  officers on
    any such bonds shall constitute  execution  of such bonds on behalf of
    the Company by such officer or officers of  the Company for the purposes
    of the Indenture, as hereby amended, and shall be  valid and effective
    for all purposes, provided that all bonds shall always be executed on
    behalf of the Company by the signature, manual or facsimile, of its
    President or a Vice-President and of its Secretary or an  Assistant
    Secretary, and provided, further, that none of such bonds shall  be
    executed  on behalf of the Company by the  same  officer  or person
    acting in more than one capacity; and

          (b)   such corporate seal of the Company may be a facsimile,  and
    any bonds of said Series on which such facsimile seal shall be affixed,
    impressed,  imprinted or reproduced shall be deemed to be  sealed  with
    the corporate seal of the Company for the purposes of the Indenture, as
    hereby  amended, and such facsimile seal shall be valid  and  effective
    for all purposes.

         SECTION 7.

          (a)   Except  as provided in subsections (c) and (g)  below,  the
    holder  of  all  of the bonds of Series 1997-2 shall be the  Depository
    Trust  Company ("DTC") and the bonds of said Series shall be registered
    in the name of Cede & Co., as nominee for DTC.

          (b)  The bonds of Series 1997-2 shall be initially issued in  the
    form  of  a  separate single authenticated fully registered certificate
    for  each  maturity  thereof in the name of  Cede  &  Co.  and  in  the
    aggregate  principal amount of the bonds of Series 1997-2 (the  "Global
    Bonds").   Upon initial issuance, the ownership of such bonds  of  said
    Series shall be registered in the bond register kept by the Trustee  in
    the  name  of Cede & Co., as nominee of DTC.  So long as the  bonds  of
    said  Series are evidenced by Global Bonds, the Trustee and the Company
    may  treat DTC (or its nominee) as the sole and exclusive holder of the
    bonds  of  Series  1997-2 registered in its name for  the  purposes  of
    payment of the principal of, premium, if any, and interest on the bonds
    of  said  Series or portion thereof to be redeemed, and of  giving  any
    notice permitted or required to be given to holders under the Indenture
    and neither the Trustee nor the Company shall be affected by any notice
    to  the  contrary.  Neither the Trustee nor the Company shall have  any
    responsibility  or  obligation to any of DTC's  participants  (each,  a
    "Participant"), any person claiming a beneficial ownership in the bonds
    of  Series  1997-2  under or through DTC or any  Participant  (each,  a
    "Beneficial Owner"), or any other person which is not shown on the bond
    register  maintained by the Trustee as being a holder, with respect  to
    the  accuracy of any records maintained by DTC or any Participant,  the
    payment  by  DTC  or any Participant of any amount in  respect  of  the
    principal of, premium, if any, or interest on the bonds of said Series;
    any  notice which is permitted or required to be given to holders under
    the  Indenture of bonds of Series 1997-2; the selection by DTC  or  any
    Participant of any person to receive payment in the event of a  partial
    redemption of the bonds of Series 1997-2 maturing June 1, 2017; or  any
    consent given or other  action  taken by DTC as bondholder.  The Trustee
    shall  pay  all principal  of,  premium, if any, and interest on the
    bonds  of  Series 1997-2 registered in the name of Cede & Co. only to or
    "upon the  order of" DTC (as that term is used in the Uniform Commercial
    Code as adopted in  Illinois  and New York), and all such payments shall
    be  valid  and effective to fully satisfy and discharge the Company's
    obligations with respect  to  the  principal of, premium, if any, and
    interest  on  such bonds  of said Series to the extent of the sum or
    sums so paid.  Except as  otherwise  provided in Section 7(c) and (g)
    below, no person  other than  DTC shall receive authenticated bond
    certificates evidencing  the obligation of the Company to make payments
    of principal of, premium, if any, and interest on the bonds of said
    Series.  Upon delivery by DTC to the Trustee of written notice to the
    effect that DTC has determined  to substitute  a  new nominee in place
    of Cede & Co., and subject  to  the provision of the Indenture with
    respect to transfers of bonds, the word "Cede  &  Co." in this
    Supplemental Indenture shall refer to  such  new nominee of DTC.

          (c)   All Global Bonds shall be exchangeable for bonds of  Series
    1997-2  in  certificated form registered in the names  of  Participants
    and/or  Beneficial Owners if, but only if, (i) DTC notifies the Company
    that  it is unwilling or unable to continue as Depository for bonds  of
    said Series or at any time ceases to be a clearing agency registered as
    such  under the Securities Exchange Act of 1934, as amended,  (ii)  the
    Company  instructs  the  Trustee  that  such  Global  Bonds  shall   be
    exchangeable  or (iii) there shall have occurred and be  continuing  an
    event  of  default or an event that with notice or passage of time,  or
    both,  would  constitute an event of default.  In any such  event,  the
    Trustee  shall  issue,  transfer  and  exchange  bond  certificates  as
    requested by DTC in appropriate amounts pursuant to Article  I  of  the
    Indenture  and Section 1 of this Supplemental Indenture.   The  Company
    shall  pay  all costs in connection with the production, execution  and
    delivery  of such bond certificates.  If bond certificates are  issued,
    the provisions of the Indenture shall apply to, among other things, the
    transfer  and exchange of such certificates and the method  of  payment
    and principal of, premium, if any, and interest on such certificates.

          (d)   Notwithstanding  any other provision of  this  Supplemental
    Indenture  to the contrary, so long as any bonds of Series  1997-2  are
    evidenced  by Global Bonds, registered in the name of Cede  &  Co.,  as
    nominee of DTC, all payments with respect to the principal of, premium,
    if  any, and interest on the bonds of said Series and all notices  with
    respect  to  the  bonds  of  said  Series  shall  be  made  and  given,
    respectively, to DTC as provided in the representation letter  relating
    to  the  bonds  of said Series among DTC, the Trustee and the  Company.
    The  Trustee is hereby authorized and directed to comply with all terms
    of the representation letter.

          (e)   In connection with any notice or other communication to  be
    provided  pursuant to the Indenture for the bonds of Series  1997-2  by
    the  Company or the Trustee with respect to any consent or other action
    to be taken by the holders of the bonds of said Series, the Company or
    the Trustee, as the case may be, shall seek to establish a record date
    to the extent permitted by the Indenture for such consent or  other
    action and give DTC notice of such record date not less  than fifteen
    (15) calendar days in advance of such record date to the extent
    possible.  Such notice to DTC shall be given only when DTC is the  sole
    holder.

           (f)   NEITHER  THE  COMPANY  NOR  THE  TRUSTEE  WILL  HAVE   ANY
    RESPONSIBILITY  OR  OBLIGATIONS TO THE PARTICIPANTS OR  THE  BENEFICIAL
    OWNERS  WITH  RESPECT TO (1) THE ACCURACY OF ANY RECORDS MAINTAINED  BY
    DTC  OR  ANY PARTICIPANT; (2) THE PAYMENT BY DTC OR ANY PARTICIPANT  OF
    ANY  AMOUNT DUE TO ANY BENEFICIAL OWNER IN RESPECT OF THE PRINCIPAL OF,
    PREMIUM,  IF  ANY, OR INTEREST ON THE BONDS OF SERIES 1997-2;  (3)  THE
    DELIVERY  BY  DTC  OR ANY PARTICIPANT OF ANY NOTICE TO  ANY  BENEFICIAL
    OWNER  WHICH IS REQUIRED OR PERMITTED UNDER THE TERMS OF THE  INDENTURE
    TO  BE GIVEN TO HOLDERS; (4) THE SELECTION OF THE BENEFICIAL OWNERS  TO
    RECEIVE PAYMENT IN THE EVENT OF ANY PARTIAL REDEMPTION OF THE BONDS  OF
    SAID  SERIES 1997-2 MATURING JUNE 1, 2017; OR (5) ANY CONSENT GIVEN  OR
    OTHER ACTION TAKEN BY DTC AS A HOLDER.

          SO  LONG  AS CEDE & CO. IS THE REGISTERED HOLDER OF THE BONDS  OF
    SERIES 1997-2 AS NOMINEE OF DTC, REFERENCES HEREIN TO THE BONDS OF SAID
    SERIES  OR  REGISTERED HOLDERS OF THE BONDS OF SAID SERIES  SHALL  MEAN
    CEDE  &  CO. AND SHALL NOT MEAN THE BENEFICIAL OWNERS OF THE  BONDS  OF
    SAID SERIES NOR DTC PARTICIPANTS.

          (g) No Global Bond may be transferred except as a whole by DTC to
    a  nominee  of DTC or by a nominee of DTC to DTC or another nominee  of
    DTC or by DTC or any such nominee to a successor of DTC or a nominee of
    such successor.

          (h)  Upon the termination of the services of DTC with respect  to
    the bonds of Series 1997-2 pursuant to subsection (c) of this Section 7
    after which no substitute book-entry depository is appointed, the bonds
    of  said  Series shall be registered in whatever name or names  holders
    transferring  or  exchanging bonds of said Series  shall  designate  in
    accordance with the provisions of the Indenture.

                           ARTICLE II

          SECTION  1.   Sections 10 and 16 of Article III of the  Indenture
are,  and  each  of  them  is, hereby amended by  striking  out  the  words
"Series L, Newton, Series W through Series Z, Series 1995-1 and Series 1997-
1"  wherever the same occur in each of said sections, and by inserting,  in
lieu  thereof, the words "Series W through Series Z, Series 1995-1,  Series
1997-1  and Series 1997-2" and the Company hereby covenants and  agrees  to
observe and comply with the provisions of said sections as hereby amended.

                          ARTICLE III

          SECTION  1.  The provisions of this supplemental indenture  shall
become  and  be  effective  from and after the execution  hereof,  and  the
Indenture, as hereby amended, shall remain in full force and effect.

           SECTION  2.   Each  reference  in  the  Indenture,  or  in  this
supplemental indenture, to any article, section, term or provision  of  the
Indenture shall mean and be deemed to refer to such article, section,  term
or  provision of the Indenture, as hereby amended, except where the context
otherwise indicates.

          SECTION  3.   All  the  covenants, provisions,  stipulations  and
agreements  in this supplemental indenture contained are and shall  be  for
the  sole and exclusive benefit of the parties hereto, their successors and
assigns, and of the holders and Registered Owners from time to time of  the
bonds and of the coupons issued and outstanding from time to time under and
secured by the Indenture, as hereby amended.

          This  supplemental indenture has been executed  in  a  number  of
identical counterparts, each of which so executed shall be deemed to be  an
original.

          At  the time of the execution of this supplemental indenture, the
aggregate  principal amount of all indebtedness of the Company outstanding,
or  to  be  presently outstanding, under and secured by the  Indenture,  as
hereby  amended, taking into account the provision for payment at  maturity
of $43,000,000 of First Mortgage Bonds, Series X, 6-1/8%, due July 1, 1997,
is  $366,000,000,  evidenced by First Mortgage Bonds of the  series  listed
below, issued by the Company under said Indenture and now outstanding or to
be presently issued by it under said Indenture, as follows:

                                                    Principal
   Series  Interest Rate (%)  Maturity Date          Amount ($)
   ------  -----------------   ---------------      -----------

     W          7-1/8           May 15, 1999         50,000,000
     W          8-1/2           May 15, 2022         33,000,000
     X          7-1/2           July 1, 2007         50,000,000
     Y          6-3/4           September 15, 2002   23,000,000
     Z           6              April 1, 2000        25,000,000
     Z           6-3/8          April 1, 2003        40,000,000
   1995-1        6.49           June 1, 2005         20,000,000
   1997-1        6.52           March 15, 1999        5,000,000
   1997-1        6.60           September 15, 1999    5,000,000
   1997-1        6.68           March 15, 2000        5,000,000
   1997-1        6.75           September 15, 2000    5,000,000
   1997-1        6.83           March 15, 2001        5,000,000
   1997-1        6.89           September 15, 2001    5,000,000
   1997-1        6.94           March 15, 2002        5,000,000
   1997-1        6.96           September 15, 2002    5,000,000
   1997-1        6.99           March 15, 2003        5,000,000
   1997-2        6.73           June 1, 2001         20,000,000  (a)
   1997-2        7.05           June 1, 2006         20,000,000  (a)
   1997-2        7.61           June 1, 2017         40,000,000  (a)
                                                     ----------
                    TOTAL........                   366,000,000



(a)  To be presently issued by the Company under said Indenture.

          IN  WITNESS WHEREOF, said Central Illinois Public Service Company
has  caused  this instrument to be executed in its corporate  name  by  its
President or a Vice President and its corporate seal or a facsimile thereof
to  be hereunto affixed and to be attested by its Secretary or an Assistant
Secretary,  and said First Trust National Association, for the  purpose  of
entering  into  and  joining with the Company  in  the  execution  of  this
supplemental  indenture, has caused this instrument to be executed  in  its
corporate  name by one of its Assistant Vice Presidents and  its  corporate
seal  to  be  hereunto  affixed  and to be attested  by  one  of  its  Vice
Presidents,  and said F. Sgaraglino, for the purpose of entering  into  and
joining  with the Company in the execution of this supplemental  indenture,
has  signed  and sealed this instrument; all as of the day and  year  first
above written.
                              CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
                              
                              
                              
                              By        ______________
                                        W. A. Koertner
                                        Vice President
(CORPORATE SEAL)

ATTEST:

     ______________
     R. C. Porter
     Assistant Secretary
                              FIRST TRUST NATIONAL ASSOCIATION



                              By       _____________
                                       Larry Kusch
                                       Assistant Vice President
(CORPORATE SEAL)

ATTEST:

        ________________
        H. H. Hall, Jr.
        Vice President and
         Assistant Secretary
                              _____________                          (SEAL)
                              F. Sgaraglino


STATE OF ILLINOIS       )
                        )    ss
COUNTY OF SANGAMON      )


         I, Kendra S. Holmes, a Notary Public in and for said County in the
State aforesaid, do hereby certify that William A. Koertner, Vice President
of  CENTRAL  ILLINOIS PUBLIC SERVICE COMPANY, a corporation  organized  and
existing  under  the laws of the State of Illinois, and Robert  C.  Porter,
Assistant Secretary of said corporation, who are both personally  known  to
me  to  be  the  same persons whose names are subscribed to  the  foregoing
instrument as such officers, respectively, of said corporation, and who are
both  personally known to me to be such officers, appeared before  me  this
day  in  person  and  severally acknowledged that they signed,  sealed  and
delivered said instrument as their free and voluntary act as such officers,
and  as  the free and voluntary act of said corporation, for the  uses  and
purposes therein set forth.

         Given under my hand and official seal this 5th day of June, 1997.



                                            Notary Public

(NOTARIAL SEAL)
STATE OF ILLINOIS  )
                   )    ss
COUNTY OF COOK     )


          I,  Sandra Rhoden, a Notary Public in and for said County in  the
State aforesaid, do hereby certify that:

          (a)   Larry  Kusch, an Assistant Vice President  of  FIRST  TRUST
    NATIONAL  ASSOCIATION, a national banking association, and H. H.  Hall,
    Jr., a Vice President and Assistant Secretary of said association,  who
    are  both personally known to me to be the same persons whose names are
    subscribed  to the foregoing instrument as such officers, respectively,
    of said association, and who are both personally known to me to be such
    officers,   appeared  before  me  this  day  in  person  and  severally
    acknowledged that they signed, sealed and delivered said instrument  as
    their  free  and voluntary act as such officers, and as  the  free  and
    voluntary  act  of said association, for the uses and purposes  therein
    set forth; and

          (b)   F. Sgaraglino, 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,  sealed  and
    delivered said instrument as his free and voluntary act, for  the  uses
    and purposes therein set forth.

         Given under my hand and official seal this 3rd day of June, 1997.


                              
                                        Sandra Rhoden
                                        Notary Public
(NOTARIAL SEAL)