The constitutive model and equivalent deformation modulus of an arbitrary column in representative elementary volume (REV) of fractured rock mass are derived. The deformation of fractured rock mass is composed of the rock part and the fracture part. The elasto-visco-plastic property is considered in this model. For the convenience in engineering practice, the complex elasto-visco-plastic model and its equivalent modulus are degraded, and the rock is taken as an elastic body. By statistical analysis of the geometric positions of the column and the fracture, the equivalent modulus of rock mass with arbitrary fractures is obtained. The constitutive model and equivalent deformation modulus of an arbitrary column in representative elementary volume (REV) of fractured rock mass are. The deformation of fractured rock mass is composed of the rock part and the fracture part. The elasto-visco-plastic property is For the convenience in engineering practice, the complex elasto-visco-plastic model and its equivalent modals are degraded, and the rock is taken as an elastic body. By statistical analysis of the geometric positions of the column and the fracture , the equivalent modulus of rock mass with arbitrary fractures is obtained.