Fuller formula is used to translate three dimensional particle grades into probability of arbitrary aggregates diameter in two dimensional plane.Crumb rubber concrete(CRC) is dispersed to form structure with three phrases composite materials,coarse aggregates,rubber crumbs and mortar.The random distribution model of coarse aggregates and rubber crumbs is established.Normal concrete is made of aggregates and mortar matrix.CRC is assumed to be composite material of two phases of concrete and rubber crumbs.The finite element method is employed to simulate the uniaxial compression strength.The results is in accord with those of the experiment well.It is demonstrated that the numerical method can be used to forecast the strength of CRC in uniaxial load approximately.The stress distributions in the micro-level structure of CRC are presented,which can explain the mechanics behavior of CRC in uniaxial condition.