Finite element method and boundary element method are numerical methods for continuum. These methods are widely used for rock mass and ground. But, it is difficult for these methods to handle large-scale deformation and destruction. On the other hand, DEM (distinct element method) devised by P. Cundall is useful for discontinuity body analysis. Especially this method got a lot of attention as a solution for a large deformation problem involved with destruction. Researches on distinct element method have been carried out by many researchers such as P. Cundall, M. Hakuno and M. Hisatake. Distinct element method has its roots in P. Cundall’s numerical analysis which tracked a block behavior in 1971.