Abstract：Based on the analysis of the tip stress field of the compression-shear mixed-mode crack，the initial angle of compression-shear mixed-mode crack is deduced according to the minimum J2 criterion. By considering the rock compression-shear mixed-mode fracture and the rock yield criterion together，two fracture criteria of the rock compression-shear mixed-mode crack are obtained by use of Mohr-Coulumb and Drucker-Prager yield criteria which are adopted widely used in geotechnical materials. The calculation results show that the fracture criteria of the rock compression-shear mixed-mode crack based on the strength criteria are rational；and that the ratio between the fracture toughness of pure type II crack and pure type I crack is related with the Poisson¢s ratio and the inner friction angle of the rock when the initial angle of the pure type II crack is a fixed value，instead of other rock mechanical parameters.
