Abstract: A theoretical model to describe the damage zone of semi-infinite concrete, which was subjected to high velocity normal penetration, was developed on the basis of implosion theory and kinetic equation combined with the factors of volumetric deformation, erosion effect, mass conservation, momentum conservation and energy transformation. Numerical solutions of the developed model show that the dynamic properties of concrete and projectile have significant effect on the penetration response. Some response zone would be disappeared when the hit velocity is high, and the aperture and damage diameter in crack/crush zone would increase substantially with the increase of hit velocity.