Abstract: Jointed rocks with regular joint sets are treated as the unity of isotropic intact rock element and equivalent anisotropic rock element with joints. An equivalent continuum model is proposed and principal formulas of equivalent deformation and equivalent strength are obtained by carefully analyzing the deformation and strength character of rock element with joints. The character of jointed rocks is simulated by non-linear FEM analysis. The effectiveness of above model is verified by physical model tests. The proposed numerical model was used to predict the strength of jointed rocks in a typical engineering project with satisfactory results.