UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549


                                    FORM 10-Q

[X]  QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934

     For Quarterly Period Ended March 31, 2002

[  ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
     EXCHANGE ACT OF 1934

For The Transition Period From                          to

                         Commission file number 1-3672.

                     CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
             (Exact name of registrant as specified in its charter)


                Illinois                                        37-0211380
     (State or other jurisdiction of                         (I.R.S. Employer
     incorporation or organization)                          Identification No.)



               607 East Adams Street, Springfield, Illinois 62739
              (Address of principal executive offices and Zip Code)


                         Registrant's telephone number,
                       including area code: (217) 523-3600


     Indicate  by check mark  whether the  registrant  (1) has filed all reports
required to be filed by Section 13 or 15(d) of the  Securities  Exchange  Act of
1934  during  the  preceding  12 months  (or for such  shorter  period  that the
registrant was required to file such reports),  and (2) has been subject to such
filing requirements for the past 90 days.


                       Yes        X     .      No             .
                           -------------          ------------



Shares outstanding of each of registrant's classes of common stock as of May 10,
  2002: Common Stock, no par value, held by Ameren Corporation (parent company
  of Registrant) - 25,452,373



<PAGE>


                     CENTRAL ILLINOIS PUBLIC SERVICE COMPANY

                                      INDEX

                                                                           Page
                                                                           ----
PART I       Financial Information

   ITEM 1.   Financial Statements

             Balance Sheet at March 31, 2002 and December 31, 2001.........   2

             Statement of Income for the three months ended
             March 31, 2002 and 2001.......................................   3

             Statement of Cash Flows for the three months ended
             March 31, 2002 and 2001.......................................   4

             Statement of Common Stockholder's Equity for the three months
             ended March 31, 2002 and 2001.................................   5

             Notes to Financial Statements.................................   6

   ITEM 2.   Management's Discussion and Analysis of Financial Condition
             and Results of Operations.....................................   9

   ITEM 3.   Quantitative and Qualitative Disclosures About Market Risk....  13

PART II      Other Information

   ITEM 1.   Legal Proceedings.............................................  16

   ITEM 6.   Exhibits and Reports on Form 8-K..............................  16

SIGNATURE..................................................................  17

<PAGE>

PART I.   FINANCIAL INFORMATION

ITEM 1.  Financial Statements
<TABLE>
<CAPTION>

                     CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
                                  BALANCE SHEET
                     (In Millions, Except Per Share Amounts)

                                                         March 31,  December 31,
                                                           2002        2001
                                                         ---------  ------------
                                                        (Unaudited)
<S>                                                        <C>        <C>
ASSETS:
Property and plant, at original cost:
   Electric                                                 $1,233     $1,224
   Gas                                                         282        280
                                                            ------     ------
                                                             1,515      1,504
   Less accumulated depreciation and amortization              704        693
                                                            ------     ------
                                                               811        811
Construction work in progress                                   10         11
                                                            ------     ------
         Total property and plant, net                         821        822
                                                            ------     ------
Investments and other assets:
   Intercompany notes receivable                               419        419
   Intercompany tax receivable                                 173        177
   Other assets                                                 18         17
                                                            ------     ------
         Total investments and other assets                    610        613
                                                            ------     ------
Current assets:
   Cash and cash equivalents                                    22         26
   Accounts receivable - trade (less allowance for
        doubtful accounts of $2 and $1, respectively)          126        119
   Other accounts and notes receivable                          31         61
   Intercompany notes receivable                                43         43
   Intercompany tax receivable                                  14         18
   Materials and supplies, at average cost -
      Fossil fuel                                               14         33
      Other                                                     10          9
   Other                                                         7          7
                                                            ------     ------
         Total current assets                                  267        316
                                                            ------     ------
Regulatory assets                                               31         32
                                                            ------     ------
Total Assets                                                $1,729     $1,783
                                                            ======     ======

CAPITAL AND LIABILITIES:
Capitalization:
   Common stock, no par value, 45.0 shares
     authorized - 25.5 shares outstanding                   $  120     $  120
   Retained earnings                                           430        444
                                                            ------     ------
      Total common stockholder's equity                        550        564
   Preferred stock not subject to mandatory
    redemption                                                  80         80
   Long-term debt                                              574        579
                                                            ------     ------
         Total capitalization                                1,204      1,223
                                                            ------     ------

Current liabilities:
   Current maturity of long-term debt                           33         33
   Accounts and wages payable                                   72        114
   Accumulated deferred income taxes                            20         20
   Taxes accrued                                                29         23
   Other                                                        37         31
                                                            ------     ------
         Total current liabilities                             191        221
                                                            ------     ------

Accumulated deferred income taxes                              250        255
Accumulated deferred investment tax credits                     12         12
Regulatory liabilities                                          36         36
Other deferred credits and liabilities                          36         36
                                                            ------     ------
Total Capital and Liabilities                               $1,729     $1,783
                                                            ======     ======

See Notes to Financial Statements.

</TABLE>

                                       2
<PAGE>
<TABLE>
<CAPTION>

                     CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
                               STATEMENT OF INCOME
                                    UNAUDITED
                                  (In Millions)

                                                           Three Months Ended
                                                                March 31,
                                                           ------------------
                                                            2002        2001
                                                            ----        ----
<S>                                                        <C>         <C>
OPERATING REVENUES:
   Electric                                                 $150        $156
   Gas                                                        65         106
                                                            ----        ----
      Total operating revenues                               215         262

OPERATING EXPENSES:
   Operations
      Fuel and purchased power                               105         108
      Gas                                                     44          80
      Other                                                   33          30
                                                            ----        ----
                                                             182         218
   Maintenance                                                 8           7
   Depreciation and amortization                              12          12
   Income taxes                                                1           5
   Other taxes                                                 9           9
                                                            ----        ----
       Total operating expenses                              212         251
                                                            ----        ----

OPERATING INCOME                                               3          11

Miscellaneous, net                                             9          10

INCOME BEFORE INTEREST CHARGES                                12          21

INTEREST CHARGES                                              10          10
                                                            ----        ----

NET INCOME                                                     2          11

PREFERRED STOCK DIVIDENDS                                      1           1
                                                            ----        ----
NET INCOME AFTER PREFERRED STOCK DIVIDENDS                  $  1        $ 10
                                                            ====        ====

See Notes to Financial Statements.
</TABLE>
                                       3

<PAGE>
<TABLE>
<CAPTION>

                     CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
                             STATEMENT OF CASH FLOWS
                                    UNAUDITED
                                  (In Millions)

                                                              Three Months Ended
                                                                   March 31,
                                                             -------------------
                                                                 2002     2001
                                                                 ----     ----
<S>                                                             <C>      <C>

Cash Flows From Operating:
   Net income                                                    $  2     $ 11
   Adjustments to reconcile net income to net cash
       provided by operating activities:
         Depreciation and amortization                             12       12
         Deferred income taxes, net                                (5)      (5)
           Changes in assets and liabilities:
               Receivables, net                                    23       (7)
               Materials and supplies                              18       13
               Accounts and wages payable                         (42)     (10)
               Taxes accrued                                        6        9
               Other, net                                          15       15
                                                                 -----    -----
Net cash provided by operating activities                          29       38

Cash Flows From Investing:
   Construction expenditures                                      (12)      (9)
                                                                 -----    -----
Net cash used in investing activities                             (12)      (9)

Cash Flows From Financing:
   Dividends on common stock                                      (15)       -
   Dividends on preferred stock                                    (1)      (1)
   Redemptions:
      Long-term debt                                               (5)      (5)
      Intercompany notes payable                                    -      (20)
                                                                 -----    -----
Net cash used in financing activities                             (21)     (26)
                                                                 -----    -----

Net change in cash and cash equivalents                            (4)       3
Cash and cash equivalents at beginning of year                     26       30
                                                                 -----    -----
Cash and cash equivalents at end of period                       $ 22     $ 33
                                                                 =====    =====

Cash paid during the periods:
   Interest (net of amount capitalized)                          $  6     $  9
   Income taxes, net                                             $  -     $  -

See Notes to Financial Statements.

</TABLE>
                                       4
<PAGE>
<TABLE>
<CAPTION>

                     CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
                    STATEMENT OF COMMON STOCKHOLDER'S EQUITY
                                    UNAUDITED
                                  (In Millions)


                                                            Three Months Ended
                                                                  March 31,
                                                          ---------------------
                                                            2002         2001
                                                            ----         ----
<S>                                                       <C>          <C>

Common stock                                               $ 120        $ 120

Retained earnings
   Beginning balance                                         444          435
   Net income                                                  2           11
   Common stock dividends                                    (15)           -
   Preferred stock dividends                                  (1)          (1)
                                                           ------       ------
                                                             430          445

Total common stockholder's equity                          $ 550        $ 565
                                                           ======       ======

</TABLE>

See Notes to Financial Statements.


                                       5
<PAGE>




CENTRAL ILLINOIS PUBLIC SERVICE COMPANY
NOTES TO FINANCIAL STATEMENTS (UNAUDITED)
March 31, 2002


NOTE 1 - Summary of Significant Accounting Policies

Basis of Presentation

     Our financial  statements  reflect all  adjustments  (which include normal,
recurring adjustments) necessary, in our opinion, for a fair presentation of the
interim  results.  These  statements  should  be read in  conjunction  with  the
financial statements and the notes thereto included in our 2001 Annual Report on
Form 10-K.

When we refer to AmerenCIPS, our, we or us, we are referring to Central Illinois
Public Service  Company.  All dollar amounts are in millions,  unless  otherwise
indicated.

Accounting Changes

     In January 2001,  we adopted  Statement of Financial  Accounting  Standards
(SFAS) No. 133, "Accounting for Derivative  Instruments and Hedging Activities."
The impact of that adoption was immaterial to us.

     On January 1, 2002, we adopted SFAS No. 141,  "Business  Combinations," and
SFAS No. 142, "Goodwill and Other Intangible Assets." SFAS 141 requires business
combinations to be accounted for under the purchase method of accounting,  which
requires  one  party  in the  transaction  to be  identified  as  the  acquiring
enterprise  and for that party to allocate the purchase  price to the assets and
liabilities  of the acquired  enterprise  based on fair market  value.  SFAS 142
requires  goodwill  and  indefinite-lived  intangible  assets  recorded  in  the
financial statements to be tested for impairment at least annually,  rather than
amortized over a fixed period,  with  impairment  losses  recorded in the income
statement.  SFAS  141 and SFAS 142 did not  have  any  effect  on our  financial
position, results of operations or liquidity upon adoption.

     In July 2001, SFAS No. 143,  "Accounting for Asset Retirement  Obligations"
was issued.  SFAS 143 requires an entity to record a liability and corresponding
asset  representing the present value of legal  obligations  associated with the
retirement  of tangible,  long-lived  assets.  SFAS 143 is  effective  for us on
January 1, 2003.  At this time,  we are  assessing the impact of SFAS 143 on our
financial position, results of operations or liquidity upon adoption.

     On January 1, 2002, we adopted SFAS No. 144, "Accounting for the Impairment
or Disposal of Long-Lived  Assets." SFAS 144 addresses the financial  accounting
and reporting for the impairment or disposal of long-lived assets and supersedes
SFAS 121, "Accounting for the Impairment of Long-Lived Assets and for Long-Lived
Assets to be Disposed Of." SFAS 144 retains the guidance  related to calculating
and  recording  impairment  losses,  but adds  guidance  on the  accounting  for
discontinued  operations,  previously accounted for under Accounting  Principles
Board  Opinion  No.  30.  SFAS  144 did not  have any  effect  on our  financial
position, results of operations or liquidity upon adoption.

NOTE 2 -  Rate and Regulatory Matters

Illinois

     In December  1997,  the Governor of Illinois  signed the  Electric  Service
Customer  Choice and Rate Relief Law of 1997 (the  Illinois  Law)  providing for
electric  utility  restructuring  in  Illinois.   This  legislation   introduced
competition  into the retail  supply of electric  energy in  Illinois.  Illinois
residential  customers  were  offered  choice  in  suppliers  on  May  1,  2002.
Industrial  and  commercial  customers  were already  offered  this choice.  The
offering of choice to our  industrial  and  commercial  customers  has not had a
material  adverse  effect on our  business  and we do not expect the offering of
choice to our  residential  customers to have a material  adverse  effect on our
business either.

     In addition,  the Illinois  Law contains a provision  freezing  residential
electric rates through January 1, 2005. Legislation has been introduced in the

                                       6
<PAGE>


Illinois House of  Representatives  and Senate that would extend the rate freeze
to December 31, 2006. At this time, we cannot predict  whether that  legislation
will ultimately be passed.

Federal - Midwest ISO and Alliance RTO

     In December 1999, the Federal Energy  Regulatory  Commission  (FERC) issued
Order 2000 requiring all utilities, subject to FERC jurisdiction, to state their
intentions  for joining a regional  transmission  organization  (RTO).  RTOs are
independent organizations that will functionally control the transmission assets
of utilities in order to improve the wholesale power market. Since January 2001,
we along with several other  utilities have been seeking  approval from the FERC
to  participate  in an RTO known as the Alliance RTO. We had  previously  been a
member of the Midwest  Independent  System Operator (MISO) and recorded a pretax
charge to earnings in 2000 of $8 million  ($5 million  after  taxes) for an exit
fee and other  costs  when we left  that  organization.  We felt the  for-profit
Alliance RTO business  model was superior to the  not-for-profit  MISO  business
model and provided us with a more equitable return on our transmission assets.

     In late 2001,  the FERC issued an order that  rejected the formation of the
Alliance RTO and ordered the Alliance RTO  companies and the MISO to discuss how
the Alliance RTO business model could be accommodated  within the MISO. On April
25,  2002,  after the Alliance  RTO and MISO failed to reach an  agreement,  and
after a series of filings by the two  parties  with the FERC,  the FERC issued a
declaratory  order  setting forth the division of  responsibilities  between the
MISO and the National  Grid (the  managing  member of the  transmission  company
formed by the Alliance  companies)  and approved the rate design and the revenue
distribution  methodology proposed by the Alliance companies.  However, the FERC
denied a request by the Alliance  companies  and the  National  Grid to purchase
certain  services  from the MISO at  incremental  cost  rather  than MISO's full
tariff  rates.  The FERC also  ordered  the MISO to return  the exit fee paid by
Ameren to leave the MISO,  provided Ameren returns to the MISO and agrees to pay
its proportional  share of the startup and ongoing  operational  expenses of the
MISO.  Moreover,  the FERC required the Alliance  companies to select the RTO in
which they will  participate  within thirty days of the order.  At this time, we
continue to evaluate our  alternatives and are in the process of determining the
impact  that the FERC's  April  2002  ruling  will have on our future  financial
condition, results of operations or liquidity.

NOTE 3 - Related Party Transactions

     Our Company has  transactions  in the normal course of business with Ameren
Corporation,  our parent company,  and its subsidiaries.  These transactions are
primarily  comprised of power  purchases and sales,  including  power  purchases
derived  under an  electric  power  supply  agreement  between  our  Company and
AmerenEnergy  Marketing Company  (Marketing  Company),  and services received or
rendered.   An  electric  power  supply   agreement  was  entered  into  between
AmerenEnergy  Generating  Company  (Generating  Company)  and  its  nonregulated
affiliate,  Marketing  Company,  also a wholly-owned  subsidiary of AmerenEnergy
Resources Company (Resources  Company).  In addition,  Marketing Company entered
into a separate power supply  agreement with our Company to supply us sufficient
energy and capacity to meet our obligations as a public utility through December
31, 2004 (Power Supply Agreement). A portion of the capacity and energy supplied
by  Generating  Company to  Marketing  Company will be resold to our Company for
resale to native load  customers at rates  specified  by the  Illinois  Commerce
Commission  (ICC),  which  approximate  the  historical   regulatory  rates  for
generation,  or to retail customers allowed choice of an electric supplier under
state law at market-based prices. In turn, we will bill these customers at rates
which  approximate  the costs we incur for our capacity  and energy  supplied by
Marketing  Company.  Through the Power Supply Agreement we purchased $98 million
of power for the three  months  ended  March 31,  2002  (March  31,  2001 - $101
million).

     Intercompany  power  purchases  totaled  $105  million for the three months
ended March 31, 2002 (March 31, 2001 - $107 million).  Intercompany  power sales
totaled $7 million for the three  months  ended March 31, 2002 (March 31, 2001 -
$6 million).  As of March 31, 2002,  intercompany  receivables included in other
accounts and notes receivable were  approximately $20 million (December 31, 2001
- $22 million). As of March 31, 2002, intercompany payables included in accounts
and wages payables totaled  approximately  $53 million  (December 31, 2001 - $87
million).

     We have the ability to borrow up to approximately  $831 million from Ameren
or Union Electric Company  (AmerenUE),  an affiliate,  through a regulated money
pool  agreement.  The total  amount  available  to us at any given time from the
regulated  money  pool is reduced by the amount of  borrowings  by  AmerenUE  or

                                       7

<PAGE>

Ameren  Services  Company,  an affiliate,  but  increased to the extent  Ameren,
AmerenUE or Ameren  Services  have surplus funds and the  availability  of other
external  borrowing sources.  Our Company,  AmerenUE and Ameren Services rely on
the regulated  money pool to coordinate and provide for certain  short-term cash
and working  capital  requirements.  Ameren  Services  administers the regulated
money pool. Interest is calculated at varying rates of interest depending on the
composition of internal and external funds in the regulated  money pool. For the
three months ended March 31, 2002 the average  interest  rate for the  regulated
money pool was 1.79% (March 31, 2001 - 5.50%).  For the three months ended March
31, 2002, the Company had no intercompany  receivables outstanding (December 31,
2001 - $24 million) and $762 million available through the regulated money pool.

     Support  services  provided by Ameren  Services  are based on actual  costs
incurred.  For the three months ended March 31, 2002,  Other Operating  Expenses
provided by Ameren Services totaled $16 million (March 31, 2001 - $13 million).

     We  incurred  a  deferred  intercompany  tax  gain,  which  resulted  in an
additional  deferred tax liability when we transferred  our electric  generating
assets and liabilities,  at historical net book value, to Generating  Company, a
subsidiary of Resources Company in May 2000. An intercompany tax receivable with
Generating  Company was established  for the deferred tax liability.  This asset
and  liability  will be amortized  over twenty  years.  At March 31,  2002,  our
deferred  tax  liability  and  intercompany  tax  receivable  was  $187  million
(December 31, 2001 - $195 million)  including the current portion of $14 million
(December 31, 2001 - $18 million).

     Our   intercompany   note  receivable   from  Generating   Company  totaled
approximately  $462 million  including the current  portion of $43 million as of
March 31, 2002 and December 31, 2001. Our intercompany  interest income recorded
in  Miscellaneous,  net for the  three  months  ended  March 31,  2002,  totaled
approximately $8 million (March 31, 2001 - $10 million).

NOTE 4 - Segment Information

Segment  information  for the three  months ended March 31, 2002 and 2001 was as
follows:
--------------------------------------------------------------------------------
Three months ended March 31, 2002:             Electric      Gas        Total
--------------------------------------------------------------------------------
Revenues                                         $150         $65        $215
Operating Income                                   (1)          4           3
--------------------------------------------------------------------------------
Three months ended March 31, 2001:
--------------------------------------------------------------------------------
Revenues                                         $156        $106        $262
Operating Income                                   3            8          11
--------------------------------------------------------------------------------

NOTE 5 - Subsequent Event


     On  April  28,  2002,  Ameren  entered  into  an  agreement  with  The  AES
Corporation to purchase all of the outstanding  stock of CILCORP Inc. CILCORP is
the  parent  company of  Peoria-based  Central  Illinois  Light  Company,  which
operates as CILCO.  Ameren also  agreed to acquire  AES Medina  Valley (No.  4),
L.L.C. which indirectly owns a 40 megawatt, gas-fired electric generation plant.
The total purchase price is  approximately  $1.4 billion,  subject to adjustment
for changes in CILCORP's working capital, and includes the assumption of CILCORP
and AES Medina Valley debt at closing,  estimated at approximately $900 million,
with the balance of the  purchase  price in cash.  Ameren  currently  expects to
finance a  significant  portion  of the cash  component  of the  purchase  price
through the issuance of new common equity.

     The purchase  will  include  CILCORP's  regulated  natural gas and electric
businesses  in Illinois  serving  approximately  200,000 and 205,000  customers,
respectively,  of which  150,000  are  combination  electric  or gas  customers.
CILCO's  territory is  contiguous  to our service  territory.  In addition,  the
purchase includes approximately 1,200 megawatts of largely coal-fired generating
capacity most of which is expected to be nonregulated by closing.

     Upon completion of the acquisition,  expected within 12 months,  CILCO will
become an Ameren subsidiary,  but will remain a separate utility company,  known
as  AmerenCILCO.  The  transaction  is subject to the  approval of the ICC,  the
Securities  and Exchange  Commission,  the FERC,  the  expiration of the waiting
period under the Hart-Scott-Rodino Act and other customary closing conditions.

     For the period  ended  December  31,  2001,  CILCORP  had  revenues of $815
million,  operating  income of $126  million,  and net  income  from  continuing
operations of $28 million,  and as of December 31, 2001 had total assets of $1.8
billion.

                                       8
<PAGE>

ITEM 2.  Management's Discussion and Analysis of Financial Condition and
         Results of Operations.

OVERVIEW

     Central  Illinois  Public Service  Company  operates as AmerenCIPS and is a
wholly-owned  subsidiary of Ameren  Corporation.  Our principal  business is the
regulated  transmission  and distribution of electricity and the distribution of
natural gas to  residential,  commercial,  industrial,  and  wholesale  users in
Illinois.  Ameren is a holding  company  registered  under  the  Public  Utility
Holding  Company  Act  of  1935  (PUHCA).  Ameren's  principal  business  is the
generation,  transmission and distribution of electricity,  and the distribution
of natural gas to residential, commercial, industrial and wholesale users in the
central  United  States.  In  addition  to  us,  Ameren's  principal   operating
subsidiaries and our affiliates are as follows:

o    Union Electric  Company,  which operates a regulated  electric  generation,
     transmission  and  distribution  business,  and  a  regulated  natural  gas
     distribution business in Missouri and Illinois as AmerenUE.
o    AmerenEnergy  Resources  Company  (Resources  Company),  which  consists of
     nonregulated  operations.   Subsidiaries  include  AmerenEnergy  Generating
     Company (Generating Company) that operates Ameren's  nonregulated  electric
     generation  in  Missouri  and  Illinois,   AmerenEnergy  Marketing  Company
     (Marketing  Company),  which markets  power for periods over one year,  and
     AmerenEnergy  Fuels and Services  Company,  which procures fuel and manages
     the  related  risks for  Ameren-affiliated  companies.  Generating  Company
     supplies  electric power to Marketing  Company which, in turn,  supplies us
     with power under a power supply agreement (Power Supply Agreement).
o    Ameren Energy,  Inc. which serves as a power  marketing and risk management
     agent for  Ameren-affiliated  companies for  transactions of primarily less
     than one year.
o    Electric Energy, Inc. (EEI), which owns and/or operates electric generation
     and transmission  facilities in Illinois. On April 30, 2002, we transferred
     our 20% common stock interest in EEI to Ameren in the form of a dividend of
     common stock in EEI. The value of our  investment  in EEI was $1.8 million.
     Subsequently, Ameren contributed such stock to Resources Company.
o    Ameren Services  Company,  which provides shared support services to Ameren
     and its subsidiaries, including us. Charges are based upon the actual costs
     incurred by Ameren Services, as required by PUHCA.

     You should read the following discussion and analysis in conjunction with:
o    The  financial  statements  and related  notes  included in this  Quarterly
     Report on Form 10-Q.
o    Management's  Discussion and Analysis of Financial Condition and Results of
     Operations  that is  included  in our  Annual  Report  on Form 10-K for the
     period ended December 31, 2001.
o    The audited financial statements and related notes that are included in our
     Annual Report on Form 10-K for the period ended December 31, 2001.

     When we refer to  AmerenCIPS,  our, we or us, we are  referring  to Central
Illinois  Public Service  Company.  All dollar  amounts are in millions,  unless
otherwise indicated.

     Our results of  operations  and  financial  position  are  impacted by many
factors,  including  both  controllable  and  uncontrollable  factors.  Weather,
economic  conditions,  and the  actions  of key  customers  or  competitors  can
significantly impact the demand for our services.  Our results are also impacted
by seasonal  fluctuations  caused by winter heating and summer  cooling  demand.
With  nearly all of our  revenues  subject to  regulation  by various  state and
federal  agencies,  decisions by  regulators  can have a material  impact on the
price we charge for our services.  We  principally  utilize  electric  power and
natural gas in our  operations.  The prices for these  commodities can fluctuate
significantly due to the world economic and political  environment,  weather and
many other factors. We do not have a fuel recovery mechanism in Illinois, but do
have a gas cost recovery mechanism. We employ various risk management strategies
in order to try to reduce  our  exposure  to  commodity  risks  and other  risks
inherent in our business.  The reliability of our  transmission and distribution
systems,  and the  level of  operating  and  administrative  costs  and  capital
investment  are key  factors  that we seek to control in order to  optimize  our
results of operations, cash flows and financial position.


RESULTS OF OPERATIONS

     Our net income  decreased  to $2 million in the first  quarter of 2002 from
$11 million in first quarter of 2001  primarily due to the extremely mild winter
weather in our service  territory and higher  operating  expenses.  According to
National  Weather  Service  data,  there were  approximately  12% fewer  heating
degree-days in our service territory in the first quarter of 2002 as compared to
2001 and normal weather conditions. As a result,  weather-sensitive  residential

                                       9
<PAGE>


electric  kilowatt-hour  sales decreased by 8% and gas sales decreased by 16% in
the first  quarter of 2002 compared to 2001.  In addition,  industrial  electric
kilowatt-hour sales decreased 4% due to the continued soft economy.

Recent Developments

     On  April  28,  2002,  Ameren  entered  into  an  agreement  with  The  AES
Corporation to purchase all of the outstanding  stock of CILCORP Inc. CILCORP is
the  parent  company of  Peoria-based  Central  Illinois  Light  Company,  which
operates as CILCO.  Ameren also  agreed to acquire  AES Medina  Valley (No.  4),
L.L.C. which indirectly owns a 40 megawatt gas-fired electric  generation plant.
The total purchase price is  approximately  $1.4 billion,  subject to adjustment
for changes in CILCORP's working capital, and includes the assumption of CILCORP
and AES Medina Valley debt at closing,  estimated at approximately $900 million,
with the balance of the  purchase  price in cash.  Ameren  currently  expects to
finance a  significant  portion  of the cash  component  of the  purchase  price
through the issuance of new common equity.

     The purchase  will  include  CILCORP's  regulated  natural gas and electric
businesses  in Illinois  serving  approximately  200,000 and 205,000  customers,
respectively,  of which  150,000 are  combination  electric  and gas  customers.
CILCO's service territory is contiguous to our service  territory.  In addition,
the  purchase  includes  approximately  1,200  megawatts  of largely  coal-fired
generating capacity most of which is expected to be nonregulated by closing.

     Upon completion of the acquisition,  expected within 12 months,  CILCO will
become  an  Ameren  subsidiary,  but will  remain a  separate  utility  company,
operating  as  AmerenCILCO.  The  transaction  is subject to the approval of the
Illinois Commerce Commission,  the Securities and Exchange Commission (SEC), the
Federal  Energy  Regulatory  Commission  (FERC),  the  expiration of the waiting
period under the Hart-Scott-Rodino Act and other customary closing conditions.

     For the period  ended  December  31,  2001,  CILCORP  had  revenues of $815
million,  operating  income of $126  million,  and net  income  from  continuing
operations of $28 million,  and as of December 31, 2001 had total assets of $1.8
billion.

     As a  result  of the  continuing  uncertainty  associated  with  AmerenUE's
pending  Missouri  electric rate case, and the CILCORP  transaction  and related
assumption of debt,  credit rating  agencies  placed Ameren  Corporation's  debt
under review for possible downgrade or negative credit watch.  Standard & Poor's
placed the ratings of our debt and AmerenUE's  debt on negative credit watch and
placed the  ratings of  Generating  Company's  debt on  positive  credit  watch.
However,  Standard & Poor's stated they expect the corporate  credit  ratings of
Ameren  and  its  subsidiaries  to be  in  the  "A"  rating  category  following
completion of the acquisition. Moody's Investor Service stated they envisioned a
one notch  downgrade of Ameren's  issuer,  senior  unsecured debt and commercial
paper ratings.  Currently,  Ameren's corporate credit rating is A+ at Standard &
Poor's and A2 at Moody's. If the ratings of AmerenUE's first mortgage bonds fall
below investment  grade,  lenders under AmerenUE's $300 million revolving credit
facility may elect not to make advances  and/or declare  outstanding  borrowings
due and payable.  In  addition,  a decrease in Ameren's  ratings may  indirectly
reduce our access to capital and/or  increase the costs of borrowings  resulting
in a negative impact on earnings.

Electric Operations

     The following table represents the favorable  (unfavorable)  variations for
the three months ended March 31, 2002 from the comparable period in 2001.

--------------------------------------------------------------------------------
                                                               Three Months
--------------------------------------------------------------------------------
Operating Revenues:
Effect of abnormal weather (estimate)                              $(4)
Growth and other (estimate)                                          -
Wholesale sales                                                     (1)
Interchange sales                                                   (1)
--------------------------------------------------------------------------------
                                                                    (6)

Purchased Power:                                                   $(3)
--------------------------------------------------------------------------------
                                                                    (3)
--------------------------------------------------------------------------------
Change in electric margin                                          $(3)
--------------------------------------------------------------------------------

                                       10
<PAGE>

     Electric margins decreased $3 million and electric revenues decreased 4% in
the first  three  months of 2002  compared  to the  year-ago  quarter.  Electric
revenues  were  negatively  impacted by the  previously-mentioned  warmer winter
weather and the decrease in industrial  sales  resulting from the continued soft
economy in our service territory. Interchange and wholesale sales also decreased
for the quarter. Purchased power costs decreased $3 million for the three months
ended March 31, 2002 compared to the same period in 2001 due to the lower energy
prices and reduced native load demand.

Gas Operations

     Our gas  revenues  decreased  $41 million and our gas costs  decreased  $36
million, in the first quarter 2002 as compared to the year-ago quarter primarily
due to a 16%  reduction in sales caused by the milder  winter  weather and lower
natural gas prices. As a result,  our gas margins decreased by $5 million in the
first quarter of 2002 as compared to the same period a year ago.

Other Operating Expenses

     Other operating  expenses increased $3 million in the first quarter of 2002
compared  to the  year-ago  period,  primarily  due to higher  costs  related to
hardware  and  software  maintenance  upgrades  for  several  computer  systems,
increases in employee  benefits costs related to the  investment  performance of
pension plan assets and increasing  healthcare  costs.  Ameren Services provided
services to us for the three  months ended March 31, 2002 of  approximately  $16
million  (March 31, 2001 - $13 million)  that were  included in other  operating
expenses. See Note 3 - "Related Party Transactions" to the financial statements.

     Maintenance  expenses  increased  $1 million  in the first  quarter of 2002
compared to the year-ago period, primarily due to higher tree-trimming expenses,
which were accelerated, in part, to take advantage of the mild weather.

Taxes

     Income  tax  expense  decreased  $4  million  in the first  quarter of 2002
compared to the year-ago period, primarily due to lower operating income.

Other Income and Deductions

     Other income and  deductions  decreased $1 million in the first  quarter of
2002 compared to the year-ago period primarily due to less intercompany interest
received on the Generating Company  subordinated  promissory note due to a lower
amount outstanding.

LIQUIDITY AND CAPITAL RESOURCES

Operating

     Our cash flows provided by operating activities decreased $9 million to $29
million in the first quarter of 2002 compared to the year-ago period,  primarily
due to a decrease in net income  coupled  with the timing of receipt of payments
from our  affiliates  offset  by a  decrease  in  accounts  payable  as the cash
received was used to reduce outstanding liabilities.

     The  tariff-based  gross  margins  of  our  operations  continue  to be our
principal  source of cash from  operating  activities.  Our  diversified  retail
customer mix of residential,  commercial and industrial  classes and a commodity
mix of gas and electric service provide a reasonably  predictable source of cash
flows. We plan to utilize short-term debt to support normal operations and other
temporary capital requirements. We are authorized by the SEC under PUHCA to have
up to $250 million of short-term  unsecured debt instruments  outstanding at any
one time.  External  short-term  borrowings  consist  of  commercial  paper with
maturities generally within 1 to 45 days.

     At March 31, 2002, we had committed  bank lines of credit  aggregating  $25
million,  all of which were unused and available at such date.  These lines make
available  interim  financing at various rates of interest  based on LIBOR,  the
bank  certificate  of  deposit  rate or other  options.  The lines of credit are
renewable  annually at various  dates  throughout  the year.  Ameren  expects to

                                       11
<PAGE>

replace  these lines of credit  prior to their  maturity.  For the three  months
ended March 31, 2002, our Company had no outstanding short-term borrowings.

     Our Company has the ability to borrow up to approximately $831 million from
Ameren or AmerenUE,  through a regulated money pool agreement.  The total amount
available  to us at any given time from the  regulated  money pool is reduced by
the amount of  borrowings by AmerenUE or Ameren  Services,  but increased to the
extent  Ameren,   AmerenUE  or  Ameren   Services  have  surplus  funds  or  the
availability  of other external  borrowing  sources.  Our Company,  AmerenUE and
Ameren  Services rely on the regulated  money pool to coordinate and provide for
certain  short-term  cash and  working  capital  requirements.  Ameren  Services
administers the regulated money pool. Interest is calculated at varying rates of
interest  depending on the  composition  of internal  and external  funds in the
regulated  money pool.  For the three months  ended March 31, 2002,  the average
interest  rate for the  regulated  money pool was 1.79% (2001 - 5.50%).  For the
three months ended March 31, 2002, the Company had no  intercompany  receivables
outstanding (December 31, 2001 - $24 million) and $762 million available through
the regulated money pool.

     Our and our affiliates'  short-term  financial agreements include customary
default  provisions  that could impact the continued  availability  of credit or
result in the  acceleration  of  repayment.  These  events  include  bankruptcy,
defaults in payment of other  indebtedness,  certain judgments that are not paid
or insured, or failure to meet or maintain covenants.  At March 31, 2002, we and
our affiliates were in compliance with these provisions.

Investing

     Our net cash used in  investing  activities  was $12  million  in the first
quarter  of 2002  (2001 - $9  million)  representing  construction  expenditures
primarily  related to  various  transmission  and  distribution  line  upgrades,
rebuilding of existing line structures,  and network facility upgrades.  Capital
expenditures are expected to approximate $59 million in 2002.

Financing

     Our net cash flows used in financing  activities totaled $21 million in the
first  quarter of 2002  compared  to $26  million in the  year-ago  period.  Our
principal financing  activities for the period included the payment of dividends
and the redemption of long-term debt.  Prior year dividends were effected by the
timing of the dividend payments.

     In the  ordinary  course of business,  we evaluate  several  strategies  to
enhance our financial position,  earnings,  and liquidity.  These strategies may
include potential acquisitions,  divestitures,  opportunities to reduce costs or
increase  revenues,  and  other  strategic  initiatives  in  order  to  increase
shareholder  value. We are unable to predict which, if any, of these initiatives
will be  executed,  as well as, the  impact  these  initiatives  may have on our
future financial position, results of operations or liquidity.

Electric Industry Restructuring

Illinois

     See Note 2 - "Rate and Regulatory Matters" to the financial statements.

Federal - Midwest ISO and Alliance RTO

     See Note 2 - "Rate and Regulatory Matters" to the financial statements.


ACCOUNTING MATTERS

Critical Accounting Policies

     Preparation  of  the  financial   statements  and  related  disclosures  in
compliance  with  generally   accepted   accounting   principles   requires  the
application of appropriate technical accounting rules and guidance, as well as

                                       12

<PAGE>

the use of estimates.  Our  application  of these  policies  involves  judgments
regarding many factors, which, in and of themselves, could materially impact the
financial  statements  and  disclosures.  A future change in the  assumptions or
judgments applied in determining the following matters, among others, could have
a material  impact on future  financial  results.  In the table  below,  we have
outlined  those  accounting   policies  that  we  believe  are  most  difficult,
subjective or complex:

<TABLE>
<CAPTION>

Accounting Policies                                Judgments/Uncertainties Affecting Application
-------------------                                ---------------------------------------------
<S>                                               <C>
Regulatory Mechanisms & Cost Recovery
                                                   o    Regulatory environment, external regulatory
   We defer costs as regulatory assets in               decisions and requirements
   accordance with SFAS 71 and make                o    Anticipated future regulatory decisions and their
   investments that we assume we will be able           impact
   to collect in future rates.                     o    Impact of deregulation and competition on
                                                        ratemaking process and ability to recover costs

Environmental Costs
                                                   o    Extent of contamination
   We accrue for all known environmental           o    Responsible party determination
   contamination, where remediation can be         o    Approved methods for cleanup
   reasonably estimated, but some of our           o    Present and future legislation and governmental
   operations have existed for over 100 years           regulations and standards
   and previous contamination may be               o    Results of ongoing research and development
   unknown to us.                                       regarding environmental impacts

Unbilled Revenue

   At the end of each period, we estimate,         o    Projecting customer energy usage
   based on expected usage, the amount of          o    Estimating impacts of weather and other usage-
   of revenue to record for services that have          affecting factors for the unbilled period
   provided to customers, but not billed. This
   period can be up to one month.

Benefit Plan Accounting

   Based on actuarial calculations, we accrue      o   Future rate of return on pension and other plan assets
   costs of providing future employee              o   Interest rates used in valuing benefit obligation
   benefits in accordance with SFAS 87,            o   Healthcare costs trend rates
   106, and 112.  See Note 9 to our financial
   statements for the year ended December 31,
   2001.

</TABLE>


Impact of Future Accounting Pronouncements

     See Note 1 - "Summary of Significant Accounting Policies" to the financial
     statements.

ITEM 3.  Quantitative And Qualitative Disclosures About Market Risk

     Market risk  represents the risk of changes in value of a physical asset or
a financial instrument, derivative or non-derivative,  caused by fluctuations in
market  variables  (e.g.,  interest rates,  etc.).  The following  discussion of
Ameren's,   including  our  Company's,   risk  management   activities  includes
"forward-looking"  statements  that  involve  risks  and  uncertainties.  Actual

                                       13
<PAGE>


results could differ  materially from those  projected in the  "forward-looking"
statements. Ameren manages market risks in accordance with established policies,
which may include entering into various derivative  transactions.  In the normal
course of  business,  Ameren  and our  Company  also face  risks that are either
non-financial or  non-quantifiable.  Such risks  principally  include  business,
legal, and operational risk and are not represented in the following analysis.

     Ameren's risk management  objective is to optimize its physical  generating
assets within prudent risk  parameters.  Risk  management  policies are set by a
Risk Management  Steering  Committee,  which is comprised of senior-level Ameren
officers.

Interest Rate Risk

     We are exposed to market risk through changes in interest rates  associated
with the  issuance  of both  long-term  and  short-term  variable-rate  debt and
fixed-rate debt, commercial paper and auction-rate  long-term debt and preferred
stock.  We manage our interest rate exposure by controlling  the amount of these
instruments we hold within our total capitalization  portfolio and by monitoring
the effects of market changes in interest rates.

     Utilizing  our debt  outstanding  at March  31,  2002,  if  interest  rates
increased by 1%, our annual interest  expense would increase by $0.3 million and
net income  would  decrease by $0.3  million.  The model does not  consider  the
effects of the reduced level of potential  overall economic  activity that would
exist in such an environment.  In the event of a significant  change in interest
rates,  management would likely take actions to further mitigate our exposure to
this market risk.  However,  due to the uncertainty of the specific actions that
would be taken and their possible effects,  the sensitivity  analysis assumes no
change in our Company's financial structure.

Safe Harbor Statement

     Statements made in this report which are not based on historical facts, are
"forward-looking"  and, accordingly,  involve risks and uncertainties that could
cause actual results to differ  materially from those  discussed.  Although such
"forward-looking"  statements  have  been  made in good  faith  and are based on
reasonable assumptions,  there is no assurance that the expected results will be
achieved.  These statements include (without limitation) statements as to future
expectations,  beliefs, plans, strategies,  objectives,  events,  conditions and
financial  performance.  In connection with the "Safe Harbor"  provisions of the
Private  Securities  Litigation  Reform  Act  of  1995,  we are  providing  this
cautionary  statement  to identify  important  factors  that could cause  actual
results to differ materially from those anticipated.  The following factors,  in
addition to those discussed elsewhere in this report and in the Annual Report on
Form 10-K for the year ended  December 31, 2001,  and in  subsequent  securities
filings,  could cause results to differ materially from management  expectations
as suggested by such "forward-looking" statements:

o    the effects of the pending  AmerenUE  excess  earnings  complaint  case and
     regulatory actions, including changes in regulatory policy;
o    changes in laws and other  governmental  actions,  including  monetary  and
     fiscal policies;
o    the impact on us of current  regulations  related  to the  opportunity  for
     customers to choose alternative energy suppliers in Illinois;
o    the  effects of  increased  competition  in the future due to,  among other
     things,  deregulation of certain aspects of the Company's  business at both
     the state and federal levels;
o    the  effects of  participation  in a  FERC-approved  Regional  Transmission
     Organization  (RTO),  including  activities  associated  with  the  Midwest
     Independent System Operator and the Alliance RTO;
o    availability and future market prices for purchased power,  electricity and
     natural gas, including the use of financial and derivative  instruments and
     volatility of changes in market prices;
o    average  rates for  electricity  in the  Midwest;
o    business  and economic conditions;
o    the impact of the adoption of new  accounting  standards;
o    interest  rates  and the  availability  of  capital;
o    actions  of rating agencies and the effects of such actions;
o    weather conditions;
o    the  effects  of  strategic   initiatives,   including   acquisitions   and
     divestitures;

                                       14
<PAGE>

o    the  impact of  current  environmental  regulations  on  utilities  and the
     expectation that more stringent  requirements will be introduced over time,
     which could potentially have a negative financial effect;
o    future wages and employee benefits costs;
o    delays in receipt of regulatory approvals for the acquisition of CILCORP or
     unexpected adverse conditions or terms of those approvals;
o    difficulties in integrating CILCO with Ameren's other businesses;
o    changes in the coal markets,  environmental  laws or  regulations  or other
     factors  adversely  impacting  synergy  assumptions in connection  with the
     CILCORP acquisition;
o    disruptions  of the  capital  markets or other  events  making  AmerenCIPS'
     access to necessary capital more difficult or costly;
o    cost and availability of transmission  capacity  required to satisfy energy
     sales made by the Company; and
o    legal and administrative proceedings.



                                       15
<PAGE>


                           PART II. OTHER INFORMATION

ITEM 1.  Legal Proceedings

     Reference is made to Item 1.  Business-Rates and Regulation - Environmental
Matters in Part I of our Annual Report on Form 10-K for the year ended  December
31, 2001 for a discussion of the February 2002 Illinois  Supreme Court  decision
which  affirmed the  Illinois  Appellate  Court's  decision  upholding  the $3.2
million  plaintiffs'  verdict  against  us in  the  lawsuit  styled  as  Zachary
Donaldson,  et al. v.  Central  Illinois  Public  Service  Company,  et al. This
lawsuit, which was filed in December 1995, alleged that, as a result of exposure
to carcinogens contained in coal tar at our former Taylorville  manufactured gas
plant site,  plaintiffs'  children  had  suffered  from a rare form of childhood
cancer known as  "neuroblastoma".  On April 1, 2002, the Illinois  Supreme Court
denied our petition for a rehearing of its February 2002  decision.  This action
leaves us with no further  appeals and  finalizes  the $3.2 million  plaintiffs'
verdict. The amount was fully accrued.

     Reference  is made to Item 3.  Legal  Proceedings  in Part I of our  Annual
Report on Form 10-K for the year ended  December 31, 2001 for a discussion  of a
number of  lawsuits  that  name our  affiliate,  AmerenUE,  our  parent,  Ameren
Corporation,  and us (which we refer to as the  Ameren  companies),  along  with
numerous  other  parties,  as  defendants  that  have been  filed by  plaintiffs
claiming varying degrees of injury from asbestos exposure.  With respect to nine
of those  lawsuits,  the Ameren  companies  have  reached  settlements  with the
plaintiffs  for  monetary  amounts not material to the Ameren  companies  and in
three cases, the Ameren companies have been voluntarily dismissed.

     Twenty-two  additional lawsuits claiming injury from asbestos exposure have
been filed against the Ameren  companies  since year-end 2001.  These  lawsuits,
like the  previous  cases,  were mostly  filed in the  Circuit  Court of Madison
County,  Illinois,  involve a large number of total defendants (over one hundred
in many  cases) and seek  unspecified  damages in excess of $50,000,  which,  if
proved, typically would be shared among the named defendants.  Currently, thirty
asbestos-related  lawsuits are pending against the Ameren companies.  We believe
that the final disposition of these proceedings will not have a material adverse
effect on our financial position, results of operations or liquidity.


ITEM 6.  Exhibits And Reports On Form 8-K

     (a) Exhibits.


     (b) Reports on Form 8-K.  None.

     Note:  Reports of Ameren Corporation on Forms 8-K, 10-Q and 10-K are on
            file with the SEC under File Number 1-14756.

            Reports of AmerenUE on Forms 8-K, 10-Q and 10-K are on file
            with the SEC under File Number 1-2967.

            Information  regarding  AmerenEnergy  Generating Company on Forms
            8-K, 10-Q, and 10-K are on file with the SEC under File Number
            333-56594.



                                       16

<PAGE>



                                    SIGNATURE

     Pursuant to the  requirements  of the Securities  Exchange Act of 1934, the
Registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned thereunto duly authorized.

                                    CENTRAL ILLINOIS PUBLIC
                                     SERVICE COMPANY
                                      (Registrant)


                                    By   /s/ Martin J. Lyons
                                       -------------------------------------
                                            Martin J. Lyons
                                              Controller
                                       (Principal Accounting Officer)



Date:  May 15, 2002



                                       17