The dynamic behavior of empty and water-filled aluminum alloy (A 6063 TD-T 3) pipes subjected to spherical projectile impact was investigated experimentally. The plastic deformation and crack growth of pipes were observed in the velocity range from 70 m/s to 260 m/s near their ballistic limit. For water-filled pipes, the plastic deformation was localized around the impact point and maximum plastic deformation was smaller than that of empty pipes. The impact velocities for crack initiation and perforation in the case of water-filled pipes were smaller than those in the case of empty pipes. In addition, the empirical equations for the energies of crack initiation and perforation of pipes were proposed. It is found that the velocities of crack initiation and cerforation for empty and water-filled pipes decrease gradually and the perforation velocities for empty and water-filled pipes approach to the same value as the pipe diameter is increased.