Abstract: The damage and rupture of fractured rock mass will accumulate and develop simultaneously during the process of its crack occurrence and growth and failure. The damage will be accumulated owing to the rupture. The damage is closely related to the rupture. Assuming the fractured rock mass as contineous mass with damage and considering the crack occurrence and growth under compressive-shear stress state and tension-shear state, the damage evolution is simulated by introducing the initial damage tensors and additional damage tensors. The two tensors are introduced into the user-defined constitutive model DLL (Dynamic Linked Library). The model is used to simulate one tunnel. Through simulation, the damage region is about twice the yield failure region. The maximum displacement of the rock mass is 0.05 m when the damage is not considered. The maximum displacement is 0.1 m when the damage is considered. The bulk and shear moduli are reduced to some extent. The proposed model is applicable for simulating the damage evolution of the rock mass. The simulated results can provide a resonable reacommendation to the engineering practices.