Abstract: The uniaxial failure mechanism of rocklike materials was analyzed using VMIB(Virtual Multi-dimensional Internal Bond) and the corresponding nonlinear constitutive relationship including failure evolution information of material was derived.From the view of VMIB,the solid materials was consisted of discrete and random mass particles.These mass particles were connected with virtual normal bonds and tangent bonds.During the processes of uniaxial compressive failure of rocklike materials,the weakness of local material stiffness was considered to result from the distribution density decrease of bond,which was induced by the local deformation in the micro scale.According to this mechanism of density decrease,a phenomenological evolution function of bond density was proposed.This evolution function was directly embedded into the VMIB constitutive relationship.The density evolutions of normal bond and tangent bond in micro scale determined different characters of material failure in macro scale respectively.The numerical simulation results and the corresponding experimental results showed that the VMIB could represent the complete process of uniaxial compressive failure of rocklike materials.Due to the fact that VMIB inherited the advantages of traditional mechanics and the molecular dynamics,it made the numerical simulation of material failure more efficient and easier.