COMMON STOCK AND WARRANT PURCHASE AGREEMENT



     THIS COMMON  STOCK AND WARRANT  PURCHASE  AGREEMENT is dated as of July 30,
2001 (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 EVA
HOLDINGS  LIMITED,  a  company  incorporated  under  the  laws of Turks & Caicos
Islands,  British West Indies, having its principal place of business located at
Gretton House, P.O. Box 65, Duke Street, Grand Turk (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 buy from the Company,  subject to the terms and  conditions set forth
herein,  $4,000,000  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
$4,000,000  (the  "Aggregate   Amount")   divided  by  the  Purchase  Price  (as
hereinafter defined),  resulting in 1,324,503 shares (the "Shares") to be issued
upon the payment of the Purchase Price.  Upon receipt of the Purchase Price, 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) As used herein "Purchase Price" shall mean $3.02.






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

     3.  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  articles 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.



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     4.  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 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  5(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




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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;

        (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.

     5. COVENANTS OF THE COMPANY.  (a) 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, 2000 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,  2000  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,



                                       4


statements and other documents required to be filed under Sections 13(a), 13(c),
14 and 15(d) of the  Exchange  Act  since  July 1, 2000 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 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,  transferable divisible warrants (the "Investor Warrants" and, together
with the Finder's Warrants,  the "Warrants") to purchase up to 331,126 shares of
Common Stock.  Such Investor  Warrants shall bear an exercise price per share of
Common Stock equal to $4.53 and shall be exercisable, immediately upon issuance,
and for a  period  of five  (5)  years  thereafter.  Subject  to the  terms  and
conditions  of the Investor  Warrants,  the Company,  at its option,  may,  upon
written  notice to the Investor,  call up to one hundred  percent  (100%) of the
Investor Warrants if the Common Stock trades at a price equal to or greater than
$6.50 per  share for five (5)  consecutive  trading  days  prior to the date the
Company calls the Investor Warrants.

        (e) Finder's Fee. The Company  acknowledges that the Shares were sold in
a private placement through the efforts of a finder (the "Finder").  The Company
agrees  to pay or  issue  to the  Finder  (the  identity  of such  Finder  to be
designated  by the Company at the  Closing),  at Closing,  cash in the amount of
three (3%) percent of the



                                       5


Aggregate Amount and transferable  divisible warrants (the "Finder's  Warrants")
to purchase such number of shares of Common Stock equal to three (3%) percent of
the Shares.  Such Finder's  Warrants  shall bear an exercise  price per share of
Common Stock equal to $4.53 and shall be exercisable, immediately upon issuance,
and for a  period  of five  (5)  years  thereafter.  Subject  to the  terms  and
conditions  of the Finder's  Warrants,  the Company,  at its option,  may,  upon
written  notice to the  Finder,  call up to one  hundred  percent  (100%) of the
Finder's Warrants if the Common Stock trades at a price equal to or greater than
$6.50 per  share for five (5)  consecutive  trading  days  prior to the date the
Company calls the Finder's Warrants.

        (f)  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  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  fees in connection with the



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negotiation and execution of this Purchase  Agreement in an amount not to exceed
an aggregate amount of $7,500.

     5. DELIVERY OF SHARES.  (a) Promptly following the delivery by the Investor
of the Total 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 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



                                       7


                             ATTN:  John F. Moynahan, 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:         EVA HOLDINGS LIMITED
                             Gretton House
                             P.O. Box 65
                             Duke Street, Grand Turk
                             Turks & Caicos Islands, British West Indies
                             ATTN:  C.B. Williams
                             Telephone No.: (649) 946-2133
                             Facsimile No.: (649) 946-2933

           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



                                       8


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 mailing a copy thereof to such party
at the address in effect for notices to it under this  Agreement 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.  This  Purchase  Agreement  shall be  governed  by and
interpreted in accordance  with the laws of the State of New York without giving
effect to choice of law provisions.

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

                          XYBERNAUT CORPORATION


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

                          EVA HOLDINGS LIMITED


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



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