Abstract: Kinetic less-lethal weapons may be the most widely used among the anti-terrorist equipments. The research on less-lethal bullet impacting process helps to uncover the injury mechanics, which was significant in increasing the hitting efficiency and safety. This paper introduces high-speed photograph to capture the process of a rubber ball impacting on a living target and a composite surrogate target. The high-speed images showed a transient and large skin deformation, which indicates the cooperation effect of water wave effect and skin straining was the major cause of an injury character-skin damage zone, pallor zone and congestive zone. Furthermore, this paper builds an analytical model for illustrating the connection between impacting effect parameters and typical injury mechanics. The experiment result and the analytical model helps to reveal the less-lethal bullet hit-pain mechanisms and to evaluate weapon efficiencies.