RE: Convertible Promissory Note

<PAGE>

                                                                     Exhibit 4.1

May 16, 2005

AETHLON MEDICAL, INC.

7825 Fay Avenue, Suite 200

La Jolla, CA 92037

RE:       Convertible Promissory Note

Dear ladies and gentleman:

The undersigned, FUSION CAPITAL FUND II, LLC ("Fusion"), hereby purchases (1) a

$30,000 Convertible Promissory Note (the "Note") of AETHLON MEDICAL INC., a

Nevada corporation (the "Company") in the form attached hereto as EXHIBIT A and

(2) a common stock purchase warrant (the "Warrant") in the form attached hereto

as EXHIBIT B to purchase 300,000 fully paid and non-assessable shares of the

Company's common stock for a purchase price of $0.25 per share. The aggregate

purchase price for the No