The interfacial adhesive property between the filler and binder matrix of HTPB propellant under 15% and zero strain were characterized by scanning electron microscope(SEM) and measuring the contact angle between the test liquids and filler AP or binder matrix respectively. The adhesive work and the interfacial tension between the filler and binder matrix were calculated. Results show that the work of adhesion (W_a) is decreased while the interfacial tension (γ_sl) is increased along with the aging time，and the interfacial adhesive of the filler/binder matrix are deteriorated under constant and zero strain. The interfacial adhesive property between the filler and binder matrix of HTPB propellant can be characterized by W_a and γsl. The value of the work of adhesion under constant strain is lower，and the interfacial tension is higher than that under zero strain. The constant strain can make the interfacial adhesive of the filler/ binder matrix deteriorate quickly.