Abstract: The RFPA (realistic failure process analysis) software is used to analyze the deformation/failure of a tunnel passing through the rock mass with incompetent laminar structural planes at different obliquities and the displacement of the key points around the tunnel, with microdimensional elements introduced in combination with the elementary constitution model based on damage mechanics and statistics. The results show that the degree of obliquities of laminar structural plane affects obviously the destabilization/failure mode of surrounding rock. The peripheral stress distribution around tunnel is asymmetrized gradually with the increasing obliquity and, eventually, the asymmetry of failure mode takes place. So, the increase in obliquity is disadvantageous to side wall. It is theoretically and practically of importance to understanding further the destabilization/failure mechanism of the tunnel passing through incompetent structural planes of rock mass and the effective measures to be taken for reinforcement.