Exhibit 4.3


                   COMMON STOCK AND WARRANT PURCHASE AGREEMENT

         THIS  COMMON  STOCK  AND  WARRANT  PURCHASE  AGREEMENT  is  dated as of
December  20,  2004  (this  "Purchase  Agreement"),  by  and  between  XYBERNAUT
CORPORATION,  a Delaware  corporation,  having its  principal  place of business
located at 12701 Fair Lakes  Circle,  Suite 550,  Fairfax,  Virginia  22033 (the
"Company"),  and WESTERN VENTURES LTD., a company incorporated under the laws of
Anguilla,  having its principal place of business located at 3 Dov Karmi Street,
Tel Aviv, Israel (the "Investor").

                               W I T N E S S E T H

         WHEREAS,  the Company wishes to sell to the Investor,  and the Investor
is willing to purchase from the Company, subject to the terms and conditions set
forth herein,  $5,000,000 (the "Purchase  Price") of shares of common stock, par
value $.01 per share (the "Common Stock"), of the Company.

         NOW, THEREFORE, for and in consideration of the premises and the mutual
agreement  contained herein and for other good and valuable  consideration,  the
receipt and  sufficiency  of which are hereby  acknowledged,  the parties hereto
agree as follows:

         1. PURCHASE AND SALE; MUTUAL  DELIVERIES.  (a) Upon the following terms
and  conditions,  the  Company  shall  issue  and sell to the  Investor  and the
Investor  shall  purchase from the Company that number of shares of Common Stock
equal to  $5,000,000  divided by $0.9272  cents per share,  which price is based
upon an  approximately  20%  discount  to the  average  closing bid price of the
Common  Stock for the ten (10)  trading  days  ending on  December  7, 2004 (the
"Closing Price"), resulting in 5,392,580 shares (the "Shares") to be issued upon
the  payment,  in cash or through  the  reduction  or  cancellation  of existing
indebtedness of the Company to the Investor, of the Purchase Price. Upon receipt
of the Purchase Price,  which payment and receipt must occur not later than 5:00
p.m. New York Time on or before Monday,  December 20, 2004 (the "Closing Date"),
the Company shall deliver to the Investor one or more certificates  representing
the Shares, bearing substantially the following legend:

         THE SECURITIES  REPRESENTED HEREBY (THE "SECURITIES") HAVE NOT
         BEEN  REGISTERED  UNDER THE SECURITIES ACT OF 1933, AS AMENDED
         (THE  "SECURITIES  ACT"),  OR THE SECURITIES LAWS OF ANY STATE
         AND MAY NOT BE SOLD OR OFFERED  FOR SALE IN THE  ABSENCE OF AN
         EFFECTIVE  REGISTRATION  STATEMENT  FOR THE  SECURITIES  OR AN
         OPINION  OF  COUNSEL  OR  OTHER  EVIDENCE  ACCEPTABLE  TO  THE
         CORPORATION THAT SUCH REGISTRATION IS NOT REQUIRED.

            (b) The Company  shall also deliver,  or cause to be delivered,  the
     original or execution copies of this Purchase Agreement.

         2.   REPRESENTATIONS  AND  WARRANTIES  OF  THE  COMPANY.   The  Company
represents and warrants to the Investor that:




            (a) The Company has the corporate  power and authority to enter into
     this Purchase  Agreement,  and to perform its  obligations  hereunder.  The
     execution  and delivery by the Company of this  Purchase  Agreement and the
     consummation by the Company of the  transactions  contemplated  hereby have
     been duly authorized by all necessary  corporate  action on the part of the
     Company.  This  Purchase  Agreement has been duly executed and delivered by
     the Company and constitute the valid and binding  obligation of the Company
     enforceable  against it in accordance with their respective terms,  subject
     to the effects of any applicable  bankruptcy,  insolvency,  reorganization,
     moratorium or similar laws  affecting  creditors'  rights  generally and to
     general equitable principles.

            (b)  Except  as set  forth  in the  SEC  Documents  (as  hereinafter
     defined),  there  is no  pending,  or to  the  knowledge  of  the  Company,
     threatened,  judicial,  administrative  or arbitral  action,  claim,  suit,
     proceeding   or   investigation   which  might   affect  the   validity  or
     enforceability of this Purchase Agreement or which involves the Company and
     which if  adversely  determined,  could  reasonably  be  expected to have a
     material  adverse  effect on the  Company and its  subsidiaries  taken as a
     whole.

            (c) No consent or approval of, or exemption by, or filing with,  any
     party or governmental or public body or authority is required in connection
     with the execution,  delivery and performance under this Purchase Agreement
     or the taking of any action contemplated hereunder or thereunder.

            (d) The Company has been duly organized and is validly existing as a
     corporation  in good  standing  under the laws of the  jurisdiction  of its
     incorporation.

            (e) The execution, delivery and performance of this Agreement by the
     Company, and the consummation of the transactions contemplated hereby, will
     not (i) violate any provision of the Company's certificate of incorporation
     or bylaws,  (ii)  violate,  conflict with or result in the breach of any of
     the  terms  of,  result  in a  material  modification  of  the  effect  of,
     otherwise,  give any other  contracting  party the right to  terminate,  or
     constitute  (or with notice or lapse of time or both  constitute) a default
     under,  any contract or other  agreement to which the Company is a party or
     by or to which the Company or any of the Company's assets or properties may
     be bound or subject, (iii) violate any order, judgment,  injunction,  award
     or decree of any court,  arbitrator or  governmental  or regulatory body by
     which the Company, or the assets or properties of the Company are bound and
     (iv) to the Company's knowledge, violate any statute, law or regulation.

3.       REPRESENTATIONS  AND  WARRANTIES OF THE INVESTOR.  The Investor  hereby
         represents and warrants to the Company that:

            (a) The Investor has the corporate power and authority to enter into
     this  Purchase  Agreement  and to perform its  obligations  hereunder.  The
     execution and delivery by the Investor of this Purchase Agreement,  and the
     consummation by the Investor of the transactions  contemplated hereby, have
     been duly authorized by all necessary  corporate  action on the part of the
     Investor.  This Purchase  Agreement


                                      -2-


     has been duly  executed and  delivered by the Investor and  constitute  the
     valid and binding  obligation  of the Investor,  enforceable  against it in
     accordance  with their  respective  terms,  subject  to the  effects of any
     applicable bankruptcy,  insolvency,  reorganization,  moratorium or similar
     laws  affecting  creditors'  rights  generally  and  to  general  equitable
     principles.

            (b) The execution,  delivery and performance by the Investor of this
     Purchase Agreement,  and the consummation of the transactions  contemplated
     hereby,  do not and will not  breach  or  constitute  a  default  under any
     applicable law or regulation or of any agreement,  judgment,  order, decree
     or other instrument binding on the Investor.

            (c) The Investor has such knowledge and prior substantial investment
     experience  in financial  and business  matters,  including  investment  in
     non-listed and  non-registered  securities,  and has had the opportunity to
     engage the services of an  investment  advisor,  attorney or  accountant to
     read the SEC  Documents  and to evaluate the merits and risks of investment
     in the Company and the Securities.

            (d) The Investor is an "accredited investor" as that term is defined
     in Rule 501(a) of  Regulation D  promulgated  under the  Securities  Act of
     1933, as amended (the "Securities Act").

            (e) The  Investor is not a "U.S.  Person" as that term is defined in
     Regulation S promulgated under the Securities Act.

            (f) The Investor is acquiring the Shares,  the Investor Warrants (as
     defined  in  Section  4(d)) and the shares of Common  Stock  issuable  upon
     exercise of the Investor  Warrants  (the "Warrant  Shares")  solely for the
     Investor's own account for investment and not with a view to or for sale in
     connection  with a distribution  of any of the Shares or the Warrant Shares
     (the Shares, Warrants and Warrant Shares collectively, the "Securities");

            (g) The  Investor  does not  have a  present  intention  to sell the
     Securities,   nor  a  present   arrangement  or  intention  to  effect  any
     distribution  of any of the  Securities  to or through any person or entity
     for purposes of selling,  offering,  distributing or otherwise disposing of
     any of the Securities;

            (h) The Investor  may be required to bear the  economic  risk of the
     investment  indefinitely  because  none  of the  Securities  may  be  sold,
     hypothecated or otherwise disposed of unless subsequently  registered under
     the  Securities Act and applicable  state  securities  laws or an exemption
     from registration is available.  Any resale of any of the Securities can be
     made only pursuant to (i) a registration statement under the Securities Act
     which is  effective  and  current  at the  time of sale or (ii) a  specific
     exemption from the  registration  requirements  of the  Securities  Act. In
     claiming any such exemption,  the Investor will, prior to any offer or sale
     or  distribution  of any  Securities  advise the Company and, if requested,
     provide the Company with a favorable  written  opinion of counsel,  in form
     and  substance   satisfactory  to  counsel  to  the  Company,   as  to  the
     applicability of such exemption to the proposed sale or distribution;


                                      -3-


            (i) The Investor understands that the exemption afforded by Rule 144
     promulgated by the Securities and Exchange  Commission under the Securities
     Act ("Rule 144") will not become  available  for at least one year from the
     date of payment for the  Securities  and any sales in reliance on Rule 144,
     if then  available,  can be made  only in  accordance  with the  terms  and
     conditions of that rule, including,  among other things, a requirement that
     the  Company  then be  subject  to, and  current,  in its  periodic  filing
     requirements  under the  Securities  Exchange Act of 1934,  as amended (the
     "Exchange  Act"),  and,  among other things,  a limitation on the amount of
     shares of Common Stock that may be sold in  specified  time periods and the
     manner in which the sale can be made;  that,  while  the  Company's  Common
     Stock is  registered  under the  Exchange  Act and the Company is presently
     subject to the periodic  reporting  requirements of the Exchange Act, there
     can be no assurance  that the Company will remain subject to such reporting
     obligations  or current in its filing  obligations;  and that, in case Rule
     144 is not applicable to a disposition of the  Securities,  compliance with
     the  registration  provisions of the Securities Act or some other exemption
     from such registration provisions will be required; and

            (j) The Investor  understands  that  legends  shall be placed on the
     certificates  evidencing  the  Securities to the effect that the Securities
     have not been  registered  under the  Securities  Act or  applicable  state
     securities  laws  and  appropriate  notations  thereof  will be made in the
     Company's stock books.  Stop transfer  instructions will be placed with the
     transfer agent of the securities constituting the Common Stock.

         4.  COVENANTS  OF THE COMPANY.  (a)  Registration  Rights.  The Company
covenants and agrees to enter into a registration rights agreement governing the
registration of the Securities with the Investor dated as of the date hereof.

            (b) Current  Public  Information.  The Company has furnished or made
     available  to the  Investor  true and  correct  copies of all  registration
     statements,  reports and documents,  including proxy statements (other than
     preliminary  proxy  statements),  filed with the  Securities  and  Exchange
     Commission (the "SEC") by or with respect to the Company since December 31,
     2003 and prior to the date of this  Agreement,  pursuant to the  Securities
     Act or the  Exchange  Act  (collectively,  the  "SEC  Documents").  The SEC
     Documents are the only filings made by or with respect to the Company since
     December 31, 2003 pursuant to Sections  13(a),  13(c),  14 and 15(d) of the
     Exchange Act or pursuant to the  Securities  Act. The Company has filed all
     reports,  schedules,  forms,  statements and other documents required to be
     filed under Sections  13(a),  13(c), 14 and 15(d) of the Exchange Act since
     December  31,  2003 and prior to the date of this  Agreement.  The  Company
     meets the  "Registrant  Requirement"  for eligibility to use Form S-3 under
     the  Securities  Act in order to register  the  Company's  Common Stock for
     resales.

            (c) SEC Documents.  The Company has not provided to the Investor any
     information  which according to applicable law, rule or regulation,  should
     have been  disclosed  publicly  prior to the date hereof by the Company but
     which has not been so  disclosed.  As of their  respective  dates,  the SEC
     Documents  complied,  and all similar documents filed with the SEC prior to
     the  Closing  Date  will  comply,   in  all  material   respects  with  the
     requirements of the Securities Act or the Exchange Act, as the case may


                                      -4-


     be, and rules and regulations of the SEC  promulgated  thereunder and other
     federal, state and local laws, rules and regulations applicable to such SEC
     Documents,  and none of the SEC Documents  contained,  nor will any similar
     document  filed with the SEC prior to the Closing Date contain,  any untrue
     statement of a material  fact or omitted to state a material  fact required
     to be stated therein or necessary in order to make the statements  therein,
     in light of the  circumstances  under which they were made, not misleading.
     The financial  statements of the Company included in the SEC Documents,  as
     of the dates thereof,  complied,  and all similar  documents filed with the
     SEC prior to the  Closing  Date  will  comply,  as to form in all  material
     respects with applicable  accounting  requirements  and the published rules
     and regulations of the SEC and other  applicable rules and regulations with
     respect thereto. Such financial statements were prepared in accordance with
     generally  accepted  accounting  principles  applied on a consistent  basis
     during the periods  involved  (except (i) as may be otherwise  indicated in
     such  financial  statements  or the  notes  thereto  or (ii) in the case of
     unaudited interim statements,  to the extent they may not include footnotes
     or may be condensed or summary  statements as permitted by Form 10-Q of the
     SEC) and fairly present in all material respects the financial  position of
     the Company and its  consolidated  subsidiaries as of the dates thereof and
     the consolidated  results of operations and cash flows for the periods then
     ended  (subject,  in the case of unaudited  statements,  to normal year-end
     audit adjustments).

            (d)  Warrants.  The Company  agrees to issue to the  Investor at the
     Closing Date,  transferable divisible warrants (the "Warrants") to purchase
     (i) up to  2,696,290  shares of Common  Stock  which shall bear an exercise
     price per share of Common  Stock of an amount  equal to 100% of the Closing
     Price and shall be exercisable  immediately upon issuance, and for a period
     of three (3) years following such issuance and (ii) up to 2,696,290  shares
     of Common  Stock  which  shall bear an  exercise  price per share of Common
     Stock  of an  amount  equal  to 100% of the  Closing  Price  and  shall  be
     exercisable  immediately upon issuance,  and for a period of six (6) months
     following  such  issuance.  Subject  to the  terms  and  conditions  of the
     Warrants,  the Company,  at its option,  may,  upon  written  notice to the
     Investor,  call up to one  hundred  percent  (100%) of the  Warrants if the
     Common Stock trades at a price equal to or greater than $3.00 per share for
     five (5)  consecutive  trading days prior to the date the Company calls the
     Warrants.

            (e) Reimbursement.  If (i) the Investor, other than by reason of its
     gross negligence or willful misconduct, becomes involved in any capacity in
     any action,  proceeding or investigation  brought by any stockholder of the
     Company,  in  connection  with or as a result  of the  consummation  of the
     transactions  contemplated by this Purchase Agreement,  or if such Investor
     impleaded in any such action, proceeding or investigation by any Person, or
     (ii) the Investor,  other than by reason of its gross negligence or willful
     misconduct or by reason of its trading of the Common Stock in a manner that
     is illegal  under the federal  securities  laws or other  actions,  becomes
     involved in any capacity in any action, proceeding or investigation brought
     by the Commission against or involving the Company or in connection with or
     as a result of the  consummation of the  transactions  contemplated by this
     Purchase  Agreement,  or if the  Investor is  impleaded in any such action,
     proceeding  or  investigation  by any  Person,  then in any such case,  the
     Company will  reimburse  the Investor  for its  reasonable  legal and other
     expenses (including the cost


                                      -5-


     of any investigation and preparation) incurred in connection therewith,  as
     such  expenses are  incurred.  In addition,  other than with respect to any
     such matter in which the  Investor is a named  party,  the Company will pay
     the Investor the charges, as reasonably determined by the Investor, for the
     time of any officers or employees of the Investor  devoted to appearing and
     preparing to appear as witnesses,  assisting in  preparation  for hearings,
     trials or  pretrial  matters,  or  otherwise  with  respect  to  inquiries,
     hearing,  trials,  and other proceedings  relating to the subject matter of
     this  Agreement.  The  reimbursement  obligations of the Company under this
     paragraph  shall be in  addition  to any  liability  which the  Company may
     otherwise  have,  shall  extend upon the same terms and  conditions  to any
     Affiliates  of the  Investors  who  are  actually  named  in  such  action,
     proceeding or investigation, and partners, directors, agents, employees and
     controlling  persons (if any), as the case may be, of the Investors and any
     such  Affiliate,  and shall be binding upon and inure to the benefit of any
     successors, assigns, heirs and personal representatives of the Company, the
     Investors  and any such  Affiliate  and any such  Person.  The Company also
     agrees  that  neither  the  Investor  nor  any  such  Affiliate,  partners,
     directors,   agents,  employees  or  controlling  persons  shall  have  any
     liability to the Company or any person  asserting claims on behalf of or in
     right of the Company in connection with or as a result of the  consummation
     of the transactions  contemplated by this Purchase  Agreement except to the
     extent that any losses, claims,  damages,  liabilities or expenses incurred
     by the Company  result from the gross  negligence or willful  misconduct of
     the Investor or any such Affiliate. The Company further agrees to reimburse
     the Investor for its reasonable  attorney's and other  professional fees in
     connection with the negotiation and execution of this Purchase Agreement.

            (f)  NASD  Compliance.  The  Company  shall  timely  provide  to the
     Investor a copy of all materials required to be filed by the Company and/or
     received by the Company from the National Association of Securities Dealers
     ("NASD") under Corporate Financing Rule 2710, and use reasonable efforts to
     cooperate  with the Investor and any broker selling Shares on behalf of the
     Investor to facilitate the Investor  and/or broker to obtain any additional
     consents, authorizations or approvals that may be necessary for the NASD to
     permit the Investor to sell the Shares.

         5.  DELIVERY OF SHARES.  (a)  Promptly  following  the  delivery by the
Investor  of the  Purchase  Price for the Shares in  accordance  with  Section 1
hereof, the Company will irrevocably instruct its transfer agent to issue to the
Investor legended certificates representing the Shares.

            (b) Within five (5)  business  days (such third  business  day,  the
     "Delivery  Date")  after the business day on which the Company has received
     both the notice of sale (by  facsimile or other  delivery) and the original
     Common Stock  certificate (and if the same are not delivered to the Company
     on the same date,  the date of delivery of the second of such  items),  the
     Company (i) shall  deliver,  and shall cause legal counsel  selected by the
     Company to deliver,  to its  transfer  agent (with  copies to  Investor) an
     appropriate  instruction  and opinion of such counsel,  for the delivery of
     unlegended  Shares  issuable  upon the sale of the Shares  pursuant  to the
     registration  statement  for the Shares;  provided  that such  registration
     statement at the time of sale has been declared effective by the Commission
     and  is  current  (the   "Unlegended   Shares");   and  (ii)  transmit


                                      -6-


     the  certificates  representing  the Unlegended  Shares  (together,  unless
     otherwise  instructed by the Investor,  with Common Stock not sold), to the
     Investor at the address specified in a notice of sale (which address may be
     the Investor's address for notices as contemplated by Section 6 hereof or a
     different  address)  via  express  courier,   by  electronic   transfer  or
     otherwise.

            (c) In lieu of delivering  physical  certificates  representing  the
     Unlegended  Shares, if the Company's transfer agent is participating in the
     Depository  Trust  Company  ("DTC")  Fast  Automated   Securities  Transfer
     program,  upon  request  of  the  Investor  and  its  compliance  with  the
     provisions  contained  in  this  paragraph,  so  long  as the  certificates
     therefor do not bear a legend and the Investor  thereof is not obligated to
     return such certificate for the placement of a legend thereon,  the Company
     shall use its best  efforts to cause its transfer  agent to  electronically
     transmit the Unlegended Shares by crediting the account of Investor's Prime
     Broker with DTC through its Deposit Withdrawal Agent Commission system.

         6. NOTICES.  Any notice required or permitted  hereunder shall be given
in writing (unless otherwise  specified herein) and shall be deemed  effectively
given upon  personal  delivery or seven (7) business  days after  deposit in the
United  States  Postal  Service,  by (a) advance copy by fax, and (b) mailing by
express  courier or registered or certified  mail with postage and fees prepaid,
addressed  to each of the other  parties  thereunto  entitled  at the  following
addresses,  or at such  other  addresses  as a party may  designate  by ten days
advance written notice to each of the other parties hereto.

            Company:                  Xybernaut Corporation
                                      12701 Fair Lakes Circle, Suite 550
                                      Fairfax, Virginia  22033
                                      ATTN:  Chief Financial Officer
                                      Telephone No.:  (703) 631-6925
                                      Facsimile No.:  (703) 631-3903

            with a copy to:           Jenkens & Gilchrist Parker Chapin LLP
                                      The Chrysler Building
                                      405 Lexington Avenue
                                      New York, New York  10174
                                      ATTN:  Martin Eric Weisberg, Esq.
                                      Telephone No.:  (212) 704-6000
                                      Facsimile No.:  (212) 704-6288

            Investor:                 Western Ventures Ltd.
                                      3 Dov Karmi Street
                                      Tel Aviv, Israel
                                      ATTN: Amit Lederman
                                      Telephone No.: _____________
                                      Facsimile No.: ______________



                                      -7-


            with a copy to:           Krieger & Prager LLP
                                      39 Broadway, Suite 1440
                                      New York, New York  10006
                                      Attn:  Samuel Krieger, Esq.
                                      Telephone No.:  (212) 363-2900
                                      Facsimile No.: (212) 363-2999

         7. SEVERABILITY.  If a court of competent jurisdiction  determines that
any provision of this Purchase  Agreement is invalid,  unenforceable  or illegal
for any  reason,  such  determination  shall not affect or impair the  validity,
legality and enforceability of the other provisions of this Purchase  Agreement.
If any such  invalidity,  unenforceability  or illegality of a provision of this
Purchase  Agreement becomes known or apparent to any of the parties hereto,  the
parties  shall  negotiate  promptly  and in good  faith  in an  attempt  to make
appropriate  changes and  adjustments  to such provision  specifically  and this
Purchase Agreement generally to achieve as closely as possible,  consistent with
applicable  law, the intent and spirit of such provision  specifically  and this
Purchase Agreement generally.

         8. EXECUTION IN COUNTERPARTS.  This Purchase  Agreement may be executed
in  counterparts,  each of which shall be deemed an  original,  but all of which
together shall constitute the same Purchase Agreement.

         9.  CONSENT TO  JURISDICTION.  Each of the Company and the Investor (i)
hereby  irrevocably  submits to the  jurisdiction  of the United States District
Court  sitting in the Southern  District of New York and the courts of the State
of New York located in New York county for the  purposes of any suit,  action or
proceeding  arising  out of or relating to this  Agreement  or the  transactions
contemplated hereby and (ii) hereby waives, and agrees not to assert in any such
suit, action or proceeding,  any claim that it is not personally  subject to the
jurisdiction of such court, that the suit, action or proceeding is brought in an
inconvenient  forum or that the  venue of the  suit,  action  or  proceeding  is
improper.  Each of the Company and the Investor consents to process being served
in any such suit, action or proceeding by any means permissible under applicable
law and agrees that such service shall constitute good and sufficient service of
process and notice thereof.  Nothing in this Section 9 shall affect or limit any
right to serve process in any other manner permitted by law.

         10.  GOVERNING LAW; Waiver of Jury. This Agreement shall be governed by
and  construed  in  accordance  with the laws of the State of New York,  without
regard to principles of conflicts of law thereof.  This  Agreement  shall not be
interpreted  or construed  with any  presumption  against the party causing this
Agreement to be drafted.  In any action,  suit or proceeding in any jurisdiction
arising out of or related  directly or  indirectly  to this  Agreement,  whether
brought by the Company against the Investor or the Investor against the Company,
the  Company  and  the  Investor   each  hereby   absolutely,   unconditionally,
irrevocably and expressly waives forever trial by jury.

                             [SIGNATURES CONTINUED]



                                      -8-


         IN WITNESS WHEREOF,  the parties have executed this Purchase  Agreement
as of the date first written above.

                                            XYBERNAUT CORPORATION


                                            By:
                                               ---------------------------------
                                               Name:
                                               Title:



                                            WESTERN VENTURES LTD.


                                            By:
                                               ---------------------------------
                                               Name:
                                               Title:













                                      -9-