Exhibit 10.02

                           ESCROW AGREEMENT

	ESCROW AGREEMENT (this "Agreement"), dated as of July 29, 2004, by and
	between  Human BioSystems, a California corporation with its principal
	place of business at 1127 Harker Avenue, Palo Alto, CA  94301 (the
	"Target Company");  Gottbetter & Partners, LLP with its principal place
	of business at 488 Madison Avenue, New York, NY 10022 (the "Escrow
	Agent"); and Langley Park Investments Plc, a corporation organized under
	the laws of England and Wales with its offices at 30 Farringdon Street,
	London EC4A 4HJ ("Langley").

                                    Recitals

		A.	Simultaneously with the execution of this Agreement,
		Langley and the Target Company entered into a Stock Purchase
		Agreement (the "Stock Purchase Agreement"), dated as of the date
		hereof and incorporated herein by reference, pursuant to which
		the Target Company has agreed that the Consideration Stock, and
		Langley has agreed that the Langley Consideration Shares, shall
		be deposited into escrow pursuant to this Agreement, including
		fifty percent (50%) of the Langley Consideration Shares to be
		deposited into escrow as Downside Price Protection (the "Langley
		Escrow Shares").

		B.	The Escrow Agent is willing to act as escrow agent
		pursuant to the terms of this Agreement with respect to the
		purchase of the shares of Consideration Stock.

		C.	All capitalized terms used but not defined herein shall
		have the meanings ascribed thereto in the Stock Purchase
		Agreement.

	NOW, THEREFORE, IT IS AGREED:

		1.	Deposit into Escrow.    At Closing, the Target Company
		shall (i) deposit the Langley Consideration Shares with the
		Escrow Agent, (ii) deliver blank stock powers (the "Stock
		Powers") for the Langley Escrow Shares to the Escrow Agent and
		(iii) deposit the Consideration Stock with the Escrow Agent.
		The Escrow Agent shall hold the Langley Consideration Shares,
		the Consideration Stock and the Stock Powers in escrow when
		delivered.

	2.	Terms of Escrow.  (a)  If the Market Value of the Common Stock
	two years after Closing is less than the Closing Price, the Target
	Company shall sell to Langley the number of Langley Escrow Shares (the
	"Langley Protection Shares") equal to (a) the Langley Consideration
	Shares multiplied by (b) the Percentage Decrease, at a purchase price of
	1p per Langley Consideration Share (the "Escrow Purchase Price").  The
	"Percentage Decrease" shall be equal to 1 - Market Value/the Closing
	Price. "Market Value" shall be the average of the ten (10) closing bid
	prices per share of the Common Stock during the ten (10) trading days
	immediately preceding the two year anniversary of the Closing.

 Within three (3) Business Days of the two year anniversary of the Closing,
 Langley shall (i) send a notice ("Sale Notice") to the Target Company and the
 Escrow Agent of the Langley Protection Shares to be sold by the Target Company
 to Langley, if any, and (ii) deposit the Escrow Purchase Price with the Escrow
 Agent, if necessary.  Within fourteen (14) Business Days of the Target
 Company's and the Escrow Agent's receipt of the Sale Notice and Escrow Agent's
 receipt of the Escrow Purchase Price, the Escrow Agent is authorized and
 directed (i) to pay the Escrow Purchase Price to the Target Company, if any,
 (ii) to deliver the Langley Protection Shares, if any, and the Stock Powers to
 Langley, (iii) to deliver the remaining Langley Escrow Shares, if any, to the
 Target Company, and (iv) to deliver the Stock Powers to the Target Company if
 the total number of Langley Protection Shares is zero.

(b)  	If at any time before September 30, 2004, the Langley Consideration
Shares are admitted for trading on the London Stock Exchange plc (the "London
Exchange"), the Escrow Agent is authorized and directed to distribute, within
fourteen (14) Business Days of such admittance, (i) the Consideration Stock to
Langley and (ii) fifty percent (50%) of the Langley Consideration Shares to the
Target Company.  If the Langley Consideration Shares are not admitted for
trading on the London Exchange by September 30, 2004, the Escrow Agent is
authorized and directed to distribute, no later than October 5, 2004, (i) the
Consideration Stock to the Target Company and (ii) the Langley Consideration
Shares to Langley.

	3.	Duties and Obligations of the Escrow Agent.

		(a)	The parties hereto agree that the duties and obligations
		of the Escrow Agent shall be only those obligations herein
		specifically provided and no other.  The Escrow Agent's duties
		are those of a depositary only, and the Escrow Agent shall incur
		no liability whatsoever, except as a direct result of its
		willful misconduct or gross negligence in the performance of its
		duties hereunder;

		(b)	The Escrow Agent may consult with counsel of its choice,
		and shall not be liable for any action taken, suffered or
		omitted to be taken by it in accordance with the advice of such
		counsel;

		(c)	The Escrow Agent shall not be bound in any way by the
		terms of any other agreement to which Langley and the Target
		Company are parties, whether or not the Escrow Agent has
		knowledge thereof, and the Escrow Agent shall not in any way be
		required to determine whether or not any other agreement has
		been complied with by Langley and the Target Company, or any
		other party thereto.  The Escrow Agent shall not be bound by any
		modification, amendment, termination, cancellation, rescission
		or supersession of this Agreement unless the same shall be in
		writing and signed jointly by Langley and the Target Company and
		agreed to in writing by the Escrow Agent;

		(d)	If the Escrow Agent shall be uncertain as to its duties
		or rights hereunder or shall receive instructions, claims or
		demands which, in its opinion, are in conflict with any of the
		provisions of this Agreement, the Escrow Agent shall be entitled
		to refrain from taking any action other than keeping safely the
		Consideration (as defined below) or taking certain action until
		the Escrow Agent is directed otherwise in writing jointly by
		Langley and the Target Company or by a final judgment of a court
		of competent jurisdiction;

		(e)	The Escrow Agent shall be fully protected in relying
		upon any written notice, demand, certificate or document which
		the Escrow Agent, in good faith, believes to be genuine.  The
		Escrow Agent shall not be responsible for the sufficiency or
		accuracy of the form, execution, validity or genuineness of
		documents or securities now or hereafter deposited hereunder or
		of any endorsement thereon, or for any lack of endorsement
		thereon, or for any description therein; nor shall the Escrow
		Agent be responsible or liable in any respect on account of the
		identity, authority or rights of the persons executing or
		delivering or purporting to execute or deliver any such
		document, security or endorsement;

		(f)	The Escrow Agent shall not be required to institute
		legal proceedings of any kind and shall not be required to
		defend any legal proceedings which may be instituted against it
		or in respect of the Consideration;

		(g)	If the Escrow Agent at any time, in its sole discretion,
		deems it necessary or advisable to relinquish custody of any of
		the Securities (to the extent delivered to the Escrow Agent
		pursuant hereto, the "Consideration"), it may do so by
		delivering the same to another Person that agrees to act as
		escrow agent hereunder and whose substitution for the Escrow
		Agent is agreed upon in writing by Langley and the Target
		Company; provided, however, that such successor Escrow Agent
		must be resident in the United States.  If no such escrow agent
		is selected within three (3) days after the Escrow Agent gives
		notice to Langley and the Target Company of the Escrow Agent's
		desire to so relinquish custody of the Consideration and resign
		as Escrow Agent, then the Escrow Agent may do so by delivering
		the Consideration to the clerk or other proper officer of a
		state or federal court of competent jurisdiction situate in the
		state and county of New York.  The fee of any court officer
		shall be borne  by the Target Company.  Upon such delivery, the
		Escrow Agent shall be discharged from any and all responsibility
		or liability with respect to the Consideration and this
		Agreement and each of the Target Company and Langley shall
		promptly pay all monies it may owe to the Escrow Agent for its
		services hereunder, including, but not limited to, reimbursement
		of its out-of-pocket expenses pursuant to paragraph (i) below;

		(h)	This Agreement shall not create any fiduciary duty on
		the Escrow Agent's part to Langley or the Target Company, nor
		disqualify the Escrow Agent from representing  either party
		hereto in any dispute with the other, including any dispute with
		respect to the Purchase Agreement or Debenture; provided,
		however, that in the event of such dispute, the Escrow Agent
		shall have the right to commence an interpleader action in any
		court of competent jurisdiction of the state of New York or of
		the United States located in the county and state of New York,
		deposit the Consideration with such court;

		(i)	The parties acknowledge and agree that the Escrow Agent
		is counsel to Langley.  The parties agree to, and agree not to
		object to, the Escrow Agent's engagement as Escrow Agent
		hereunder;

		(j)	Upon the full performance of this Agreement, the Escrow
		Agent shall be deemed released and discharged of any further
		obligations hereunder.

	4.	Indemnification.

		(a)	Langley hereby indemnifies and holds free and harmless
		the Escrow Agent from any and all losses, expenses, liabilities
		and damages (including but not limited to reasonable attorney's
		fees, and amounts paid in settlement) resulting from claims
		asserted by the Target Company against the Escrow Agent with
		respect to the performance of any of the provisions of this
		Agreement;

		(b)	The Target Company hereby indemnifies and holds free and
		harmless the Escrow Agent from any and all losses, expenses,
		liabilities and damages (including but not limited to reasonable
		attorney's fees, and amount paid in settlement) resulting from
		claims asserted by Langley against the Escrow Agent with respect
		to the performance of any of the provisions of this Agreement;

		(c)	Langley and the Target Company, jointly and severally,
		hereby indemnify and hold the Escrow Agent harmless from and
		against any and all losses, damages, taxes, liabilities and
		expenses that may be incurred by the Escrow Agent, arising out
		of or in connection with its acceptance of appointment as the
		Escrow Agent hereunder and/or the performance of its duties
		pursuant to this Agreement, the Purchase Agreement and the
		Securities, including, but not limited to, all legal costs and
		expenses of the Escrow Agent incurred defending itself against
		any claim or liability in connection with its performance
		hereunder, provided that the Escrow Agent shall not be entitled
		to any indemnity for any losses, damages, taxes, liabilities or
		expenses that directly result from its willful misconduct or
		gross negligence in its  performance as Escrow Agent hereunder

		(d)	In the event of any legal action or proceeding involving
		any of the parties to this Agreement which is brought to enforce
		or otherwise adjudicate any of the rights or obligations of the
		parties hereunder, the non-prevailing party or parties shall pay
		the legal fees of the prevailing party or parties and the legal
		fees, if any, of the Escrow Agent.

	5.	Miscellaneous.

		(a)	All notices, including Notices of Conversion and Notices
		of Exercise,  objections, requests, demands and other
		communications sent to any party hereunder shall be deemed duly
		given if (x) in writing and sent by facsimile transmission to
		the Person for whom intended if addressed to such Person at its
		facsimile number set forth below or such other facsimile number
		as such Person may designate by notice given pursuant to the
		terms of this Section 5 and (y) the sender has confirmation of
		transmission:

	(i)	If to the Target Company:	Human BioSystems
                                                Attn:  Harry Masuda
                                                President and CEO
                                                1127 Harker Avenue
                                                Palo Alto, CA 94301
						Tel:  (650) 323-0943
						Fax: (650) 327-8658

		(ii)	If to Langley:		Langley Park Investments PLC
						30 Farringdon Street
						London EC4A 4HJ
						Attn: Harry Pearl
						Tel: 44.207.569.0044
						Fax: 44.207.724.0090

		(iii)	If to the Escrow Agent:	Gottbetter & Partners, LLP
						488 Madison Ave.
						New York, New York 10022
						Attn:  Adam S. Gottbetter, Esq.
						Tel:  (212) 400-6900
						Fax:  (212) 400-6901

		(b)	This Agreement has been prepared, negotiated and
		delivered in the state of New York and shall be governed by and
		construed and enforced in accordance with the laws of the state
		of New York applicable to contracts entered into and performed
		entirely within New York, without giving effect to the
		principles of New York law relating to the conflict of laws.

		(c)	This Agreement may be executed in two or more
		counterparts, all of which when taken together shall be
		considered one and the same agreement and shall become effective
		when counterparts have been signed by each party and delivered
		to the other party, it being understood that both parties need
		not sign the same counterpart.  In the event that any signature
		is delivered by facsimile transmission, such signature shall
		create a valid and binding obligation of the party executing (or
		on whose behalf such signature is executed) the same with the
		same force and effect as if such facsimile signature page were
		an original thereof.

		(d)	This Agreement shall be binding upon and inure to the
		benefit of the parties and their successors and permitted
		assigns.  The assignment by a party of this Agreement or any
		rights hereunder shall not affect the obligations of such party
		under this Agreement.

	6.	Termination of Escrow.   The term of this Escrow Agreement shall
	begin upon the date hereof and shall continue until terminated upon the
	earlier to occur of (i) the Langley Escrow Shares are fully distributed
	or (ii) the written agreement of the parties to terminate this
	Agreement.  Upon the termination of this Escrow Agreement pursuant to
	subsection (ii), the Escrow Agent shall distribute any of the Langley
	Escrow Shares then held by it pursuant to the terms of the written
	agreement of the parties.


[ SIGNATURE PAGE FOLLOWS ]


	IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
	signed the day and year first above written.


     					The Target Company:

					Human BioSystems


					By: /s/ Harry Masuda
					   ____________________

					Name:Harry Masuda
					Title:President and CEO

					Langley:

					Dungarvon Associates, Inc. on behalf of
					Langley Park Investments Plc.


					By: /s/ Rufus Pearl
					    ______________________
					Name: Rufus Pearl
					Title:Administrative Director


					Escrow Agent:

					Gottbetter & Partners, LLP


					By:/s/Adam S. Gottbetter
					    ____________________________
					Name: Adam S Gottbetter
					Title: Managing Partner




EXHIBIT B

Human BioSystems

OFFICER'S CERTIFICATE

	I, Harry Masuda, being the President ofHuman BioSystems, a California
	corporation (the "Target Company"), pursuant to Section 2.2(a)(ii) of
	that certain Stock Purchase Agreement (the "Purchase Agreement"), dated
	as of July 29, 2004, by and between the Target Company and Langley Park
	Investments PLC, do hereby certify on behalf of the Target Company that
	attached hereto is a copy of the resolutions duly adopted by the Board
	of Directors of the Target Company authorizing the Target Company to
	execute and deliver the Transaction Documents, as such term is defined
	in the Purchase Agreement and to enter into the transactions
	contemplated thereby.

	IN WITNESS WHEREOF, I have executed this Officer's Certificate on behalf
of the Target Company this 29th day of July, 2004.

       Human BioSystems

       /s/Harry Masuda
      ___________________
    By:   Harry Masuda, President