Abstract：The sliding crack model has been widely applied in the damage and fracture analysis of the rock-like materials. Considering systematically the influence of the main crack direction，winged crack direction，confining pressure and the dimensionless winged crack length，six typical calculating models for I-model stress intensity factors are compared. What¢s more，for the case where the winged cracks are aligned in the direction of the principal compressive stress，a finite element analysis is carried out. Comparing the results of finite element method and those of six theoretical models，it is concluded that three models among are able to get perfect results，and one model is useable only under uniaxial loading，while the results of the other two models are obviously different from FEM results. These conclusions would be useful for the further study of damage and fracture of the rock-like materials.
