Abstract: Aggregate shape plays an important role on mechanical properties of rockfill materials and the effect of aggregate shape deserves further study. According to the actual aggregate shape of blasted rockfill, the DEM models with different sphericities are proposed. Unbreakable samples and breakable samples are established respectively, and the influence of particle sphericity on mechanical properties of rockfill and its meso-mechanism are studied. The preliminary results show that the sphericity affects the mechanical properties of rockfill by affecting the particle occlusion and particle breakage. When the particle strength is relatively high, the smaller the sphericity is, the higher the degree of particle occlusion will be, which will increase the peak friction angle. When the particle strength is relatively low, the particle breakage increases with the decrease of sphericity, which will decrease the peak friction angle. In addition, the initial tangent modulus of rockfill increases with the increase of confining pressure and sphericity.