The consequences of ship collision could be very serious, causing lots of human casualties, environmental pollution and huge economic losses. It is essential to study the collision process including two ships in water. In the past, most ship collision tests are based on the study of collision damage of local structures and there are few experiments considering the motion response of ships during the collision process. Actually, the interaction between the fluid and structure does have effects on the collision consequences. In this paper, the collision experiments of ship models are conducted in a water tank, with particular attention on structure in the collision region. Considering the coupling effect of external dynamics and internal mechanics, the dynamic responses of ships during collision are studied. The failure mode and deformation damage characteristics of ship’s side structure in collision region are also assessed. On this basis, the time history of collision forces, the damage extent of the struck structure and the energy absorption are analyzed and then the influence of velocity and ship’s mass on the results are evaluated. It provides valuable test data for validation of numerical simulation and theoretical studies.