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


                                  SCHEDULE 13D


                    UNDER THE SECURITIES EXCHANGE ACT OF 1934


                                (Amendment No. 1)


                    Kiwa Bio-Tech Products Group Corporation
--------------------------------------------------------------------------------
                                (Name of Issuer)


                    Common Stock, par value $0.001 per share
--------------------------------------------------------------------------------
                         (Title of Class of Securities)


                                    49834X106
--------------------------------------------------------------------------------
                                 (CUSIP Number)


                    Kiwa Bio-Tech Products Group Corporation
                        17700 Castleton Street, Suite 589
                       City of Industry, California 91748
                         Attention: Corporate Secretary


                                 With a copy to:


                             V. Joseph Stubbs, Esq.
--------------------------------------------------------------------------------
                         Stubbs Alderton & Markiles, LLP
                       15821 Ventura Boulevard, Suite 525
                            Encino, California 91436
       (Name, Address and Telephone Number of Person Authorized to Receive
                          Notices and Communications)


                                 April 22, 2004
--------------------------------------------------------------------------------
             (Date of Event which Requires Filing of this Statement)


If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  that is the subject of this  Schedule  13D, and is filing this
schedule  because of Rule 13d-1(e),  Rule 13d-1(f) or Rule  13d-1(g),  check the
following box. [ ]


                         (Continued on following pages)





CUSIP No. 49834X106                SCHEDULE 13D                Page 2 of 5 Pages


________________________________________________________________________________
1    NAME OF REPORTING PERSONS
     I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

        Gui-sheng Chen

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

________________________________________________________________________________
3    SEC USE ONLY



________________________________________________________________________________
4    SOURCE OF FUNDS*

        OO

________________________________________________________________________________
5    CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
     PURSUANT TO ITEMS 2(d) OR 2(e)                                   [_]



________________________________________________________________________________
6    CITIZENSHIP OR PLACE OF ORGANIZATION

        People's Republic of China

________________________________________________________________________________
               7    SOLE VOTING POWER

  NUMBER OF             -750,000- (See Response to Item 5)

   SHARES      _________________________________________________________________
               8    SHARED VOTING POWER
BENEFICIALLY
                        -0-
  OWNED BY
               _________________________________________________________________
    EACH       9    SOLE DISPOSITIVE POWER

  REPORTING             -750,000- (See Response to Item 5)

   PERSON      _________________________________________________________________
               10   SHARED DISPOSITIVE POWER
    WITH
                        -0-

________________________________________________________________________________
11   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

        750,000 (See Response to Item 5)

________________________________________________________________________________
12   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN SHARES*

                                                                      [X]

________________________________________________________________________________
13   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

        2.1% (See Response to Item 5)

________________________________________________________________________________
14   TYPE OF REPORTING PERSON*

        IN

________________________________________________________________________________
                     *SEE INSTRUCTIONS BEFORE FILLING OUT!


                                   Page 2 of 5



ITEM 1.  SECURITY AND ISSUER.

         This  amendment to Schedule 13D amends the Schedule 13D dated March 25,
2004 (the "13D").

         This  amendment to Schedule 13D relates to the common stock,  par value
$0.001  per  share  (the  "Common  Stock"),  of  Kiwa  Bio-Tech  Products  Group
Corporation,  a Utah  corporation,  formerly known as Tintic Gold Mining Company
(the "Company" or the "Issuer"), and is being filed pursuant to Rule 13d-2 under
the Securities Exchange Act of 1934, as amended (the "Exchange Act").

         The address of the principal  executive offices of the Company is 17700
Castleton Street, Suite 589, City of Industry, California 91748.

ITEM 2.  IDENTITY AND BACKGROUND.

(a)      This  Statement  is hereby  filed by  Gui-sheng  Chen  (the  "Reporting
Person").

(b)      The  business  address  of the  Reporting  Person is c/o Kiwa  Bio-Tech
Products Group Corporation, 17700 Castleton Street, Suite 589, City of Industry,
California 91748.

(c)      The  present  principal  occupation  of  the  Reporting  Person  is  in
bio-technology and agricultural research.

(d)      During the last five years, the Reporting Person has not been convicted
in a criminal proceeding (excluding traffic violations or similar misdemeanors).

(e)      During the last five years,  the Reporting  Person was not a party to a
civil proceeding of a judicial or administrative body of competent  jurisdiction
which  resulted in the Reporting  Person being subject to a judgment,  decree or
final  order  enjoining  future  violations  of,  or  prohibiting  or  mandating
activities subject to, Federal or State securities laws or finding any violation
with respect to such laws.

(f)      The Reporting Person is a citizen of the People's Republic of China.

ITEM 3.  SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

         On March 15,  2004,  pursuant to an  Agreement  and Plan of Merger (the
"Merger  Agreement") dated as of March 11, 2004, by and among Tintic Gold Mining
Company, a Utah corporation  ("Tintic"),  TTGM Acquisition  Corporation,  a Utah
corporation  and  wholly-owned  subsidiary of Tintic  ("Merger  Sub"),  and Kiwa
Bio-Tech  Products Group Ltd., a company  governed under the laws of the British
Virgin Islands  ("Kiwa"),  Merger Sub merged with and into Kiwa (the  "Merger").
Each share of Kiwa common stock was converted  into  1.5445839  shares of Tintic
Common  Stock,  with Kiwa  surviving as Tintic's  wholly-owned  subsidiary.  The
merger resulted in a change of control of Tintic,  with former Kiwa shareholders
owning  approximately  89% of Tintic  on a fully  diluted  basis.  A copy of the
Merger  Agreement  was filed as EXHIBIT A to the 13D.  Prior to the Merger,  the
Reporting  Person  held  750,000  shares  of Kiwa,  which  were  converted  into
1,158,438  shares of Tintic  Common  Stock at the closing of the Merger.  Of the
1,544,584  shares of Tintic  Common  Stock  issued at the closing of the Merger,
408,432 were issued to Peace Land Venture  Ltd. as custodian  for the  Reporting
Person.  Peace Land Venture Ltd. has voting and investment power with respect to
those shares.

         Subsequent  to the Merger,  Tintic  changed  its name to Kiwa  Bio-Tech
Products  Group  Corporation  and effected a 4-for-1  stock  split.  The 750,000
shares of Tintic Common Stock held by the Reporting  Person were  converted into
3,000,000  shares of the Common  Stock.  As of April 22, 2004,  of the 3,000,000
shares of the Common Stock issued subsequent to the stock split,  2,250,000 were
issued to


                                  Page 3 of 5



InvestLink  (China)  Limited,  formerly  known as Peace Land  Venture  Ltd.,  as
custodian for the Reporting Person.

ITEM 4.  PURPOSE OF THE TRANSACTION.

         The Reporting  Person acquired his Common Stock pursuant to the Merger.
The Reporting  Person has no plans or proposals which relate or would result in:
(a) the acquisition by any person of additional securities of the Issuer, or the
disposition  of  securities  of  the  Issuer;  (b)  an  extraordinary  corporate
transaction,  such as a merger,  reorganization  or  liquidation,  involving the
Issuer or any of its  subsidiaries;  (c) a sale or transfer of a material amount
of  assets  of the  Issuer  or any of its  subsidiaries;  (d) any  change in the
present board of directors or  management of the Issuer,  including any plans or
proposals  to change the  number or term of  directors  or to fill any  existing
vacancies on the board; (e) any material change in the present capitalization or
dividend  policy of the Issuer;  (f) any other  material  change in the Issuer's
business or corporate structure;  (g) changes in the issuer's charter, bylaws or
instruments  corresponding  thereto  or  other  actions  which  may  impede  the
acquisition  of  control  of the Issuer by any  person;  (h)  causing a class of
securities of the Issuer to be delisted from a national  securities  exchange or
to cease to be authorized to be quoted in an inter-dealer  quotation system of a
registered national securities association;  (i) a class of equity securities of
the issuer becoming eligible for termination of registration pursuant to Section
12(g)(4) of the Securities Act of 1933, as amended; or (j) any action similar to
any of those enumerated above.

ITEM 5.  INTEREST IN SECURITIES OF THE ISSUER.

(a)      The Reporting  Person is the beneficial  owner of 750,000 shares of the
Common  Stock,  or  approximately  2.1% of the Common  Stock based on a total of
34,930,248 shares of the Common Stock outstanding as of March 29, 2004.

(b)      The Reporting Person  has the sole power to vote or direct the vote and
dispose or direct the disposition of 750,000 shares of the Common Stock.

(c)      Other than the  transactions  associated  with the Merger and the stock
split  outlined in this  Information  Statement,  the  Reporting  Person has not
engaged in any transactions in the Common Stock during the past sixty (60) days.

(d)      Not applicable.

(e)      Not applicable.

ITEM 6.  CONTRACTS, ARRANGEMENTS,  UNDERSTANDINGS OR  RELATIONSHIPS WITH RESPECT
TO SECURITIES OF THE ISSUER.

         There are no contracts,  arrangements,  understandings or relationships
(legal or  otherwise)  between  the person  named in Item 2 and any person  with
respect to any  securities of the Issuer,  including but not limited to transfer
or voting of any of the  securities,  finder's  fees,  joint  ventures,  loan or
option arrangements,  puts or calls, guarantees of profits,  division of profits
or loss, or the giving or withholding of proxies.

ITEM 7.  MATERIAL TO BE FILED AS EXHIBITS.

1. The Power of Attorney is filed hereto as EXHIBIT A.


                                  Page 4 of 5



                                   SIGNATURE

         After reasonable inquiry and to the best of the undersigned's knowledge
and belief,  the  undersigned  certifies that the  information set forth in this
statement is true, complete and correct.


Date:    April 26, 2004



                                     /s/ James Nian Zhan
                                     -----------------------------
                                     James Nian Zhan, as attorney-in-fact for
                                     Gui-sheng Chen


                                  page 5 of 5



                                                                       EXHIBIT A

                               POWER OF ATTORNEY

         The undersigned  hereby constitutes and appoints James Nian Zhan as the
undersigned's true and lawful attorney-in-fact to:

         (1) execute for and on behalf of the undersigned,  in the undersigned's
capacity as an officer  and/or  director of Tintic Gold Mining  Company,  a Utah
corporation (the "COMPANY"),  Forms 3, 4, and 5 in accordance with Section 16(a)
of the Securities  Exchange Act of 1934, as amended (the "EXCHANGE ACT") and the
rules  thereunder and Schedules 13D and 13G in accordance with Regulation 13D of
the Exchange Act;

         (2) do  and  perform  any  and  all  acts  for  and  on  behalf  of the
undersigned which may be necessary or desirable to complete and execute any such
Form 3, 4, or 5, or Schedule 13D or 13G,  complete and execute any  amendment or
amendments  thereto,  and timely  file such form and  schedules  with the United
States  Securities  and Exchange  Commission  and any stock  exchange or similar
authority; and

         (3) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney-in-fact,  may be of benefit to,
in the best  interest  of, or legally  required  by, the  undersigned,  it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned  pursuant to this Power of Attorney  shall be in such form and shall
contain such terms and conditions as such  attorney-in-fact  may approve in such
attorney-in-fact's discretion.

         The undersigned hereby grants to each such  attorney-in-fact full power
and  authority  to do and  perform  any  and  every  act  and  thing  whatsoever
requisite,  necessary, or proper to be done in the exercise of any of the rights
and  powers  herein  granted,  as  fully  to all  intents  and  purposes  as the
undersigned  might  or  could  do if  personally  present,  with  full  power of
substitution  or  revocation,  hereby  ratifying  and  confirming  all that such
attorney-in-fact,  or such attorney-in-fact's  substitute or substitutes,  shall
lawfully  do or cause to be done by virtue  of this  power of  attorney  and the
rights  and  powers  herein  granted.  The  undersigned  acknowledges  that  the
foregoing  attorneys-in-fact,  in serving in such capacity at the request of the
undersigned,  are  not  assuming,  nor  is  the  Company  assuming,  any  of the
undersigned's  responsibilities  to comply with Section 16 or Regulation  13D of
the Exchange Act.

         This Power of Attorney  shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 or Schedules 13D and
13G with respect to the undersigned's holdings of and transactions in securities
issued by the Company,  unless  earlier  revoked by the  undersigned in a signed
writing delivered to the foregoing attorneys-in-fact.

         IN WITNESS  WHEREOF,  the undersigned has caused this Power of Attorney
to be executed as of this 18th day of March, 2004.

                                     /s/ Gui-sheng Chen
                                     ------------------------------
                                     Signature

                                     Gui-sheng Chen
                                     ------------------------------
                                     Print Name