Abstract: The critical state of coarse-grained soils is the important tool to study the constitutive model, however, the critical state of coarse soil considering the effect of particle breakage is not clear. The influences of particle breakage on the stress and deformation properties and the critical state of rockfills are studied through the large-scale triaxial CD tests. The main conclusions are as follows: (1) The critical-state stress ratio M_c of rockfill materials is not a constant, which is found to be passively correlated with the confining pressure. (2) While the effect of void ratio on M_c can be neglected. (3) The critical state of rockfill samples with different confining pressures and void ratios can be described by the same straight line in e-(p/p_a)^ξ plane, and the parameters of the straight line are constant.