According to the stress equivalence assumption, the damage increment of stiffness modulus of gussasphalt concrete(GA) with the accumulation of loading number is divided into 3 stages in case of using stiffness modulus as a fatigue damage parameter. The third stage, which is characterized by the distinct change of mechanical property, is defined as the stage of fatigue cracking. Based on the character of fatigue damage of GA at different temperature, the critical damage factor(Dp) for GA was defined. It is shown that there is a power function relationship between damage factor(D) and fatigue life of GA when failure. Furthermore, a fatigue damage model, considering the influence of temperature, is established by fitting the damage factor of GA with an appropriate function.