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                                                                   EXHIBIT 10.3

                         COMMON STOCK PURCHASE AGREEMENT

      THIS COMMON STOCK PURCHASE AGREEMENT is dated as of June 23, 2000 (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 DALSTON
HOLDINGS LIMITED, having an office at P.O. B. 65, Grand Turk, Turk & Caicos
Island, B.W.I. (the "Investor").

                               W I T N E S S E T H

      WHEREAS, the Company wishes sell to the Investor, and the Investor is
willing to buy from the Company, subject to the terms and conditions set forth
herein, two hundred fifty thousand (250,000) shares (the "Shares") of Common
Stock of the Company, par value $.01 per share.

      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.     MUTUAL DELIVERIES. (a) Upon the delivery by the Investor of the
sum of Three Million Five Hundred Thousand and 00/100 Dollars ($3,500,000) (the
"Purchase Price"), the Company shall deliver to the Investor one or more
certificates for 437,500 shares of Common Stock of the Company (the "Shares")
at the price equal to 88% of the Closing Bid Price on June 22, 2000 per share
(the "Purchase Price"), 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.


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             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 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, (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


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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 prior substantial investment experience,
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
this investment.

             (d)   The Investor is an "Accredited Investor" as that term is
defined in Regulation D promulgated under the Act.

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

      4.     COVENANTS OF THE COMPANY. (a) The Company covenants and agrees to
use its best efforts to register the Shares, and to include the Shares and the
Warrants set forth in Paragraph 4(d), in a registration statement to be filed
with the Securities and Exchange Commission on or before July 10, 2000.

             (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,
1998 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, 1998
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 January 1, 1999 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


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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 "Warrants") for 87,500 shares of
Common Stock. Such Warrants shall bear an exercise price per share of Common
Stock of $10.00, and shall be exercisable immediately upon issuance, and for a
period of five (5) years thereafter, in the form annexed hereto as Exhibit
4(d), together with registration rights under Paragraph 4(a) hereof. The
Warrants shall be callable by the Company if the Market Price of the Shares
exceeds 250% of the Purchase Price for any ten (10) trading days during a
fifteen (15) trading day period.

             (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 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


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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 Transaction Documents 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.

      5.     DELIVERY OF SHARES. (a) Promptly following the delivery by the
Investor of the Purchase Price for the Common Stock in accordance with Section
1 hereof, the Company will irrevocably instruct its transfer agent to issue the
Shares to the Investor with the 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
of 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
sale of the Shares pursuant to the registration statement for the Shares after
the registration statement has been declared effective by the Commission
("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 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 provided 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 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


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such other addresses as a party may designate by ten days advance written
notice to each of the other parties hereto.

<TABLE>
<S>                                     <C>
                  COMPANY:                  XYBERNAUT CORPORATION
                                            12701 Fair Lakes Circle
                                            Suite 550
                                            Fairfax, Virginia  22033
                                            ATT:  Mr. Steven Newman, Vice Chairman
                                            Telephone No.:  (703) 631-6925
                                            Facsimile No.:  (703) 631-6734

                  with a copy to:           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:         At the address set forth on the first page of this Agreement.

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

      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.     GOVERNING LAW. This Purchase Agreement shall be governed by and
interpreted in accordance with the laws of the State of New York.

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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:  Steven Newman
                   Title: Vice Chairman

                   DALSTON HOLDINGS LIMITED

                   By:
                        ------------------------------------------

                   Name:
                        ------------------------------------------

                   Title:
                         -----------------------------------------

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