Exhibit 4(a)


UNDERWRITER’S WARRANT AGREEMENT


THIS AGREEMENT, made as of July    , 2007 between NeoStem, Inc., a
Delaware corporation, with offices at 420 Lexington Avenue, Suite 450, New
York, New York 10170 (“Company”), and Mercer Capital Ltd., a
                    ,
with offices at 40 Wall Street, 31st Floor, New York, NY 10005  (“Underwriter”).


WHEREAS, the Company is engaged in a public offering (“Public Offering”) of
Units (“Units”), and in connection therewith, has determined to issue and
deliver up to 1,270,000 Units at a price of
$         per unit [in the range of $5.00 - $5.50 per unit], through the Underwriter and other
broker/dealers (arranged by the Underwriter) who are members of the National
Association of Securities Dealers (NASD). 
Each Unit consists of one share of the Company’s common stock and one-half
a Class A warrant to purchase one-half share of the Company’s common stock, par
value $0.001 per share.


WHEREAS, in connection with the Public Offering, the Company has determined to
issue and deliver to the Underwriter up to [95,250] Class A Underwriter
Warrants (“Underwriter Warrants”) [5% of the shares sold]; and


WHEREAS, each Underwriter Warrant will entitle the holder to purchase one share
of the Company’s common stock for
$         [in the range of $6.50 - $7.15]; and


WHEREAS,  the Company has filed, on July,    
2007 with the Securities and Exchange Commission a Registration Statement on
Form SB-2/A, No. 333-142923 as Pre-Effective Amendment No.3 (“Registration
Statement”), for the registration, under the Securities Act of 1933, as amended
(“Act”) of, among other securities, the Underwriter Warrants and the common
stock issuable upon exercise of the Underwriter Warrants; and


WHEREAS, the Company desires to provide for the form and provisions of the
Underwriter Warrants, the terms upon which they shall be issued and exercised,
and the respective rights, limitation of rights, and immunities of the Company
and the Underwriter; and


WHEREAS, all acts and things have been done and performed which are necessary
to make the Underwriter Warrants, when executed on behalf of the Company and
countersigned by or on behalf of the Underwriter, as provided herein, the
valid, binding and legal obligations of the Company, and to authorize the
execution and delivery of this Agreement.


NOW, THEREFORE, in consideration of the mutual agreements herein contained, the
parties hereto agree as follows:











SECTION
1:  WARRANTS


1.1.         Registration.


1.1.1.      Underwriter
Warrant Register.  The Company shall maintain books (“Warrant
Register”), for the registration of original issuance and the registration of
transfer of the Underwriter Warrants. Upon the initial issuance of the
Underwriter Warrants, the Company shall issue and register the Underwriter
Warrants in the names of the respective holders thereof in such denominations
as determined by the Company.


1.1.2.      Registered
Holder.  Prior to due presentment for registration of
transfer of any Underwriter Warrant, the Company may deem and treat the person
in whose name such Underwriter Warrant shall be registered upon the Warrant
Register (“registered holder”), as the absolute owner of such Underwriter
Warrant and of each Underwriter Warrant represented thereby (notwithstanding
any notation of ownership or other writing on the Warrant Certificate made by
anyone other than the Company), for the purpose of any exercise thereof, and
for all other purposes, and neither the Company shall be affected by any notice
to the contrary.


SECTION
2:  TERMS AND EXERCISE OF WARRANTS


2.1.         Warrant Price.  Each Underwriter Warrant shall, when countersigned by the Company,
entitle the registered holder thereof, subject to the provisions of such
Underwriter Warrant and of this Warrant Agreement, to purchase from the Company
the number of shares of Common Stock stated therein, at the price of
$         per share [in the range of $6.50 - $7.15] (the “Warrant Price”), subject to (i) the adjustments provided in Section 3
hereof, and (ii) subject to
redemption as provided in Section 5 hereof.  The term “Warrant Price” refers to the price
per share at which common stock may be purchased at the time an Underwriter
Warrant is exercised.


2.2          Duration of Underwriter Warrants.  An
Underwriter Warrant may be exercised only during the period (“Exercise Period”)
commencing one year following the initial closing of Units in the Public Offering
and thereafter until 5:00 PM New York time on 
        , 2012 [the date five
(5) years after the effective date of the Public Offering], unless earlier
redeemed (“Expiration Date”).  Except
with respect to the right to receive the Redemption Price (as set forth in
Section 6 hereunder), each Underwriter Warrant not exercised on or before
the Expiration Date shall become void, and all rights thereunder and all rights
in respect thereof under this Agreement shall cease at the close of business on
the Expiration Date. The Company in its sole discretion may extend the duration
of the Underwriter Warrants by delaying the Expiration Date.


2.3.         Exercise of Underwriter Warrants.


2.3.1.      Payment. 
Subject to the provisions of the Underwriter Warrant and this Warrant
Agreement, an Underwriter Warrant, may be exercised by the registered holder
thereof by surrendering it, at the office of the Company, in the Borough of
Manhattan, City and State of New York, with the subscription form, as set forth
in the Underwriter Warrant, duly executed, and by paying in full, in lawful
money of the United States, in cash, good certified check or good bank draft
payable to the order of the Company, the Warrant Price for each full share of
Common Stock as to which the Underwriter Warrant is exercised and any and all
applicable taxes due in connection with the exercise of the Underwriter
Warrant, the exchange of the Underwriter Warrant for the Common Stock, and the
issuance of the Common Stock.


2.3.2.      Cashless Exercise.  This Warrant
may also be exercised at such time by means of a “cashless exercise” in which
the holder shall be entitled to receive a certificate for the number of Warrant
Shares equal to the quotient obtained by dividing [(A-B)(X)] by (A), where:


(A) = the closing sales price on the Trading
Day immediately preceding the date of such election;


(B) = the Exercise
Price of this Warrant, as adjusted; and


(X) = the number of
Warrant Shares issuable upon exercise of this Warrant in accordance with the terms
of this Warrant by means of a cash exercise rather than a cashless exercise.


2.3.3.      Issuance of
Certificates.  As soon as practicable after the exercise of
any Underwriter Warrant and the clearance of the funds in payment of the
Warrant Price, the Company shall issue to the registered holder of such
Underwriter Warrant a certificate or certificates for the number of full shares
of Common Stock to which he is entitled, registered in such name or names as
may be directed by him, and if such Underwriter Warrant shall not have been
exercised in full, a new countersigned Underwriter Warrant for the number of
shares as to which such Underwriter Warrant shall not have been exercised.
Notwithstanding the foregoing, the Company shall not be obligated to deliver any
securities pursuant to the exercise of an Underwriter Warrant unless a
registration statement under the Act with respect to the Common Stock is
effective. Underwriter Warrants may not be exercised by, or securities issued
to, any registered holder in any state in which such exercise would be
unlawful.











2.3.4.      Valid
Issuance.  All shares of Common Stock issued upon the
proper exercise of an Underwriter Warrant in conformity with this Agreement
shall be validly issued, fully paid and nonassessable.


2.3.5.      Date of
Issuance.  Each person in whose name any such
certificate for shares of Common Stock is issued shall for all purposes be
deemed to have become the holder of record of such shares on the date on which
the Underwriter Warrant was surrendered and payment of the Warrant Price was
made, irrespective of the date of delivery of such certificate, except that, if
the date of such surrender and payment is a date when the stock transfer books
of the Company are closed, such person shall be deemed to have become the
holder of such shares at the close of business on the next succeeding date on
which the stock transfer books are open.


SECTION
3:  ADJUSTMENTS


3.1.         Stock
Dividends—Split-Ups.  If after the date hereof, and subject to the provisions of
Section 3.6 below, the number of outstanding shares of Common Stock is
increased by a stock dividend payable in shares of Common Stock, or by a
split-up of shares of Common Stock, or other similar event, then, on the
effective date of such stock dividend, split-up or similar event, the number of
shares issuable on exercise of each Underwriter Warrant shall be increased in
proportion to such increase in outstanding shares.


3.2           Aggregation of Shares.  If after the date hereof, and subject to
the provisions of Section 3.6, the number of outstanding shares of Common
Stock is decreased by a consolidation, combination, reverse stock split or
reclassification of shares of Common Stock or other similar event, then, on the
effective date of such consolidation, combination, reverse stock split,
reclassification or similar event, the number of shares issuable on exercise of
each Underwriter Warrant shall be decreased in proportion to such decrease in
outstanding shares.


3.3          Adjustments in Exercise Price. 
Whenever the number of shares of Common Stock purchasable upon the
exercise of the Underwriter Warrants is adjusted, as provided in
Section 3.1 and 3.2 above, the Warrant Price shall be adjusted (to the
nearest cent) by multiplying such Warrant Price immediately prior to such adjustment
by a fraction (x) the numerator of which shall be the number of shares of
Common Stock purchasable upon the exercise of the Underwriter Warrants
immediately prior to such adjustment, and (y) the denominator of which
shall be the number of shares of Common Stock so purchasable immediately
thereafter.


3.4          Replacement
of Securities upon Reorganization, etc.  In
case of any reclassification or reorganization of the outstanding shares of
Common Stock (other than a change covered by Section 3.1 or 3.2 hereof or
that solely affects the par value of such shares of Common Stock), or in the
case of any merger or consolidation of the Company with or into another
corporation (other than a consolidation or merger in which the Company is the
continuing corporation and that does not result in any reclassification or
reorganization of the outstanding shares of Common Stock), or in the case of
any sale or conveyance to another corporation or entity of the property of the
Company as an entirety or substantially as an entirety in connection with which
the Company is dissolved, the Underwriter Warrant holders shall thereafter have
the right to purchase and receive, upon the basis and upon the terms and
conditions specified in the Underwriter Warrants and in lieu of the shares of
Common Stock of the Company immediately theretofore purchasable and receivable
upon the exercise of the rights represented thereby, the kind and amount of
shares of stock or other securities or property (including cash) receivable
upon such reclassification, reorganization, merger or consolidation, or upon a
dissolution following any such sale or transfer, by a Warrant holder of the
number of shares of Common Stock of the Company obtainable upon exercise
of the Underwriter Warrants immediately prior to such event; and if any
reclassification also results in a change in shares of Common Stock covered by
Section 3.1 or 3.2, then such adjustment shall be made pursuant to
Sections 3.1, 3.2, 3.3 and this Section 3.4. The provisions of this Section 3.4
shall similarly apply to successive reclassifications, reorganizations, mergers
or consolidations, sales or other transfers.


3.5.         Notices of Changes in Warrant.  Upon
every adjustment of the Warrant Price or the number of shares issuable on
exercise of an Underwriter Warrant, the Company shall give written notice
thereof to the Underwriter, which notice shall state the Warrant Price
resulting from such adjustment and the increase or decrease, if any, in the
number of shares purchasable at such price upon the exercise of an Underwriter
Warrant, setting forth in reasonable detail the method of calculation and the
facts upon which such calculation is based. Upon the occurrence of any event
specified in Sections 3.1, 3.2, or 3.4, then, in any such event, the Company
shall give written notice to the Underwriter Warrant holder, at the last
address set forth for such holder in the warrant register, of the record date
or the effective date of the event. Failure to give such notice, or any defect
therein, shall not affect the legality or validity of such event.


3.6.         Fractional Shares.  Notwithstanding any provision contained
in this Warrant Agreement to the contrary, the 











Company shall retain the
option not to issue fractional shares upon exercise of Underwriter Warrants.
If, by reason of any adjustment made pursuant to this Section 4, the
holder of any Underwriter Warrant would be entitled, upon the exercise of such
Underwriter Warrant, to receive a fractional interest in a share, the Company
may, upon such exercise, either deliver fractional shares of Common Stock to be
issued to the Underwriter Warrant holder, or round to the nearest whole share,
or pay the fractional share in cash at the market price at the close of
business on the date the Underwriter Warrant is exercised.


3.7.         Form of Warrant.  The form of Underwriter Warrant
need not be changed because of any adjustment pursuant to this Section 3,
and Underwriter Warrants issued after such adjustment may state the same
Warrant Price and the same number of shares as is stated in the Underwriter
Warrants initially issued pursuant to this Agreement. However, the Company may
at any time in its sole discretion make any change in the form of Underwriter
Warrant that the Company may deem appropriate and that does not affect the
substance thereof, and any Underwriter Warrant thereafter issued or
countersigned, whether in exchange or substitution for an outstanding
Underwriter Warrant or otherwise, may be in the form as so changed.


SECTION
4:  TRANSFER AND EXCHANGE OF WARRANTS


4.1.         Procedure for Surrender of Underwriter
Warrants.  Underwriter
Warrants may be surrendered to the Company, together with a written request for
exchange or transfer, and thereupon the Company shall issue in exchange
therefor one or more new Underwriter Warrants as requested by the registered
holder of the Underwriter Warrants so surrendered, representing an equal
aggregate number of Underwriter Warrants; provided, however, that in the event
that an Underwriter Warrant surrendered for transfer bears a restrictive
legend, the Company shall not cancel such Underwriter Warrant and issue new
Underwriter Warrants in exchange therefor until the Company has received an
opinion of counsel for the Company stating that such transfer may be made and
indicating whether the new Underwriter Warrants must also bear a restrictive
legend.


4.2.         Service Charges.  No service charge shall be made for any
exchange or registration of transfer of Underwriter Warrants.


4.3          Limits on Transfer.  This Underwriter Warrant shall not be sold
during the offering or sold, transferred, assigned, pledged or hypothecated, or
be the subject of any hedging, short sale, derivative, put, or call transaction
that would result in the effective economic disposition of the securities by
any person for a period of 180 days immediately following the date of
effectiveness or commencement of sales of the Public Offering, except to any
member participating in the offering and the officers or partners thereof, or
as otherwise permitted under 2710(g)(2) of the NASD’s Corporate Financing Rule
and only if the warrants so transferred remain subject to the one-year lock-up
restriction for the remainder of the lock-up period.


SECTION
5:  REDEMPTION


5.1.         Redemption.  All or any part of the outstanding
Underwriter Warrants may be redeemed, at the option of the Company, at any time
after they become exercisable and prior to their expiration, at the office of
the Company, upon the notice referred to in Section 5.2, at the price of $.001
per Underwriter Warrant (“Redemption Price”), provided that the Company’s stock
closes at a price equal to or exceeding
$         [in the range of $8.00 - $8.50] for 20 consecutive trading days on its principal trading
market.


5.2.         Date Fixed for, and Notice of,
Redemption.  In the event the Company shall elect to redeem
all or any part of the Underwriter Warrants, the Company shall fix a date for
the redemption. Notice of redemption shall be mailed by first class mail,
postage prepaid, by the Company not less than 30 days prior to the date
fixed for redemption to the registered holders of the Underwriter Warrants to
be redeemed at their last addresses as they shall appear on the registration
books. Any notice mailed in the manner herein provided shall be conclusively
presumed to have been duly given whether or not the registered holder received
such notice.


5.3.         Exercise After Notice of
Redemption.  The
Underwriter Warrants may be exercised in accordance with Section 2 of this
Agreement at any time after notice of redemption shall have been given by the
Company pursuant to Section 5.2. hereof and prior to the time and date
fixed for redemption, which time shall be 5:00 PM New York time. On and after
the redemption date, the record holder of the Underwriter Warrants shall have
no further rights except to receive, upon surrender of the Underwriter
Warrants, the Redemption Price.


SECTION 6.         OTHER PROVISIONS RELATING TO RIGHTS OF
UNDERWRITER WARRANT HOLDERS


6.1.         No Rights as Stockholder.    An Underwriter Warrant does
not entitle the registered holder thereof to any of the rights of a stockholder
of the Company, including, without limitation, the right to receive dividends,
or other distributions, exercise any preemptive rights to vote or to consent or
to receive notice as stockholders in respect of the meetings of stockholders or
the election of directors of the Company or any other matter.


6.2.         Lost, Stolen, Mutilated, or Destroyed
Underwriter Warrants.    If
any Underwriter Warrant is lost, stolen, mutilated, or destroyed, the Company
may on such terms as to indemnity or otherwise as they may in their discretion
impose 











(which may include a surety
bond and shall, in the case of a mutilated Underwriter Warrant, include the
surrender thereof), issue a new Underwriter Warrant of like denomination,
tenor, and date as the Underwriter Warrant so lost, stolen, mutilated, or
destroyed. Any such new Underwriter Warrant shall constitute a substitute
contractual obligation of the Company, whether or not the allegedly lost,
stolen, mutilated, or destroyed Underwriter Warrant shall be at any time
enforceable by anyone.


6.3.         Reservation of Common Stock.  The Company shall at all times reserve
and keep available a number of its authorized but unissued shares of Common
Stock that will be sufficient to permit the exercise in full of all outstanding
Underwriter Warrants issued pursuant to this Agreement.


SECTION 7.         MISCELLANEOUS PROVISIONS


7.1.         Payment of Taxes.  The Company will from time to time
promptly pay all taxes and charges that may be imposed upon the Company in
respect of the issuance or delivery of shares of Common Stock upon the exercise
of Underwriter Warrants, but the Company shall not be obligated to pay any
transfer taxes in respect of the Underwriter Warrants or such shares.


7.2.         Successors.  All the covenants and provisions
of this Agreement by or for the benefit of the Company or the Underwriter  shall bind and inure to the benefit of their
respective successors and assigns.


7.3.          Notices.  Any notice, statement or demand
authorized by this Warrant Agreement to be given or made by the holder of any
Underwriter Warrant to or on the Company shall be sufficiently given or made if
sent by certified mail, or private courier service, postage prepaid, addressed
(until another address is filed in writing by the Company), as follows:


NeoStem, Inc.

420 Lexington Avenue
 Suite 450
 New York, New York  10170
 Attn: Catherine Vaczy, Vice President
and General Counsel


with a copy to:


Lowenstein Sandler PC

65 Livingston Avenue
 Roseland, New Jersey  07068
 Attn: Alan Wovsaniker, Esq.


Any notice, statement or
demand authorized by this Agreement to be given or made by the holder of any
Underwriter Warrant to the Company shall be sufficiently given or made if sent
by certified mail or private courier service, postage prepaid, addressed (until
another address is filed in writing by the holder), as follows:


Mercer Capital, Ltd.

40 Wall Street, 31st Floor,
 New York, NY 10005
 Attn: 



with a copy in to:


Weinstein & Schonfield ,
L.L.P.

80 Wall Street
 New York, NY  1005-3601
 Attn: 
Andrea Weinstein, Esq.


7.4          Applicable law.  The validity, interpretation, and
performance of this Agreement and of the Underwriter Warrants shall be governed
in all respects by the laws of the State of New York, without giving effect to
conflict of laws. The Company hereby agrees that any action, proceeding or
claim against it arising out of or relating in any way to this Warrant
Agreement shall be brought and enforced in the courts of the State of New York
or the United States District Court for the Southern District of New York, and
irrevocably submits to such jurisdiction, which jurisdiction shall be
exclusive. The Company hereby waives any objection to such exclusive
jurisdiction and that such courts represent an inconvenience forum. Any such
process or 











summons to be served upon the
Company may be served by transmitting a copy thereof by registered or certified
mail, return receipt requested, postage prepaid, addressed to it at the address
set forth in Section 7.2 hereof. Such mailing shall be deemed personal
service and shall be legal and binding upon the Company in any action,
proceeding or claim.


7.5.         Persons Having Rights under this
Agreement.  Nothing
in this Agreement expressed and nothing that may be implied from any of the
provisions hereof is intended, or shall be construed, to confer upon, or give
to, any person or corporation other than the parties hereto and the registered
holders of the Underwriter Warrants any right, remedy, or claim under or by
reason of this Warrant Agreement or of any covenant, condition, stipulation,
promise, or agreement hereof.  All
covenants, conditions, stipulations, promises, and agreements contained in this
Warrant Agreement shall be for the sole and exclusive benefit of the parties
hereto and their successors and assigns.


7.6          Counterparts.  This Agreement may be executed in any
number of counterparts and each of such counterparts shall for all purposes be
deemed to be an original, and all such counterparts shall together constitute
but one and the same instrument.


7.7.          Effect of Headings.  The Section headings herein are
for convenience only and are not part of this Warrant Agreement and shall not
affect the interpretation thereof.











IN WITNESS WHEREOF, this Agreement has been duly executed by the parties hereto as of the
day and year first above written.


 


	
  Attest:

  	
   

  	
   

  	
   

  	
  NEOSTEM, INC.

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
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  Attest:

  	
   

  	
   

  	
   

  	
  MERCER CAPITAL, LTD.

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  	
   

  	
   

  
	
   

  	
   

  	
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