Abstract: The derivation of elastic strength matrix in partial coordinate system for anisotropic modelling is very difficult. To solve this problem, a new method was suggested on the basis of the two coordinate systems in FEM software. The FEM software converts automatically the relation between two coordinate systems, thus the derivation of elastic strength matrix in partial coordinate system is avoided, and the calculation process of the anisotropic model was simplified. The calculation results can reflect well the effect of the direction of anisotropic rock material on stress distribution of the tunnel.