Abstract: In order to study the elastic properties of rock mass using the finite element method (FEM) approach, a reasonable rock mass meshing method is proposed, especially the way in dealing with fracture intersections and end regions; and a Fortran program is developed to generate mesh of rock mass automatically. Based on field investigation results of fracture distribution in Jinping hydropower station, a random fracture network is generated by Monte Carlo method; and the mesh of the generated fractured rock mass is created automatically by the Fortran program. Using the parameters obtained by laboratory tests on rock blocks and artificial fractures, a series of numerical simulations of mechanical deformation of the fractured rock mass at different scales and directions are conducted based on the established FEM model. The results show that the REV of deformation modulus of the rock mass is 8 m. Furthermore, the elastic compliance tensor of the fractured rock mass at REV is studied, and error of the tensor characteristic evaluation is less than 8%

Key words: fractured rock mass, deformation modulus, scale effect, anisotropy, numerical method