During the service life of a solid rocket motor, the interface of liner and propellant is subjected to cyclic loading. In order to find the damage law of it, fixed stress amplitude cyclic loading experiment was used. In the process of the experiment, constitutive behavior and dissipative energy mainly researched. The influence of the fixed stress amplitude on properties of liner/propellant was also studied. The results show that the remains strain increased following the increase of cyclic number. The dissipative energy of every cyclic loading is random, so it does not adapt to be damage variable. The stress amplitude and natural logarithm of the cycle number accord with exponent equation.