Abstract:Numerical simulation software RFPA2D is used to analysis the progressive failure process of rock with different ,the ratio of mesoscopic compressive strength to mesoscopic tensile strength. Ten rock samples are divided into five sets with 1,3,5,7 and 9,and they are subjected to uniaxial compressive loading. In order to investigate the influence of on the fracture process and failure mode of rock,the rock samples in different sets are of the same mechanical parameters except . The results show that is an important parameter of rock. With the increase of ,the macroscopic peak strength and residual strength decrease and the failure mode changes from shear failure mode to tensile failure mode. However, when decreases to a certain value, it has little influence on rock deformation and failure mode.