A roughness discrete fractures network(RDFN) model is proposed considering the complex and roughness geometry distribution of discontinuities in jointed rock masses. The digital image processing technique is firstly used to generate RDFN images using Matlab code. Then a RDFN model based on particle flow code(PFC) is established and the corresponding mechanical behaviors under uniaxial compression, such as elasticity, strength and failure pattern, are studied and compared with the traditional linear discrete fractures network (DFN) model. The results show that the elastic modulus of RDFN model is lower than that of DFN model. The peak strength of RDFN model is higher, and residual strength is lower. Microcracks in DFN model mainly coincided along the linear joints and partial intact rocks are fractured. The failure pattern of RDFN model is, however relatively much more complex with more fractured intact rocks after peak strength.