The accurate prediction of strength and deformability characteristics of rock mass is a challenging issue.In practice,properties of a rock mass are often estimated from available empirical relationships based on the uniaxial compressive strength(UCS).However,UCS does not always give a good indication of in situ rock mass strength and deformability.The aim of this paper is to present a methodology to predict the strength and deformability of a jointed rock mass using UDEC(universal distinct element code).In the study,the rock mass is modelled as an assemblage of deformable blocks that can yield as an intact material and/or slide along predefined joints within the rock mass.A range of numerical simulations of uniaxial and triaxial tests was conducted on rock mass samples in order to predict the equivalent mechanical properties for the rock mass under different loading directions.Finally,results are compared with the deformability parameters obtained by analytical methods. The accurate prediction of strength and deformability characteristics of rock mass is often estimated from available empirical relationships based on the uniaxial compressive strength (UCS) .However, UCS does not always give a good indication of in situ rock mass strength and deformability. The aim of this paper is to present a methodology to predict the strength and deformability of a joined rock mass using UDEC (universal distinct element code) .In the study, the rock mass is modelled as an assemblage of deformable blocks that can yield as an intact material and / or slide on a boundary joint of the rock mass. A range of numerical simulations of uniaxial and triaxial tests was conducted on rock mass samples in order to predict the equivalent mechanical properties for the rock mass under different loading directions. Finaally, results are compared with the deformability parameters obtained by analytical methods.