Abstract: The influences of particle breakage on hardening rule and dilatancy are studied, and the modified equations are proposed respectively. When the breakage energy is introduced into the hardening rule and dilatancy of coarse granular aggregates, a new elasto-plastic constitutive model considering the particle breakage is developed based on the concept of effective plastic work. The numerical simulations for the various confining pressure tests are performed in a developed program by use of the proposed model and the model without consideration of the particle breakage. It is shown that the proposed model can accurately describe the strength and deformation of coarse granular aggregates subjected to low and relative high confining pressures. In addition, particle breakage could decrease the shear strength and increase the compression deformation. It is verified by the simulation of 1D compression tests in discrete element method.