Abstract: Tsunami is one of the disasters that threaten the safety of coastal buildings. The impact generated by the tsunami bore wave and its carried floating debris would result in serious damage to coastal engineering structures. It is of great significance to study the movement behavior of floating debris in the tsunami wave during the propagation in coastal zones. In this study, the dam-break wave was employed to simulate the nearshore tsunami wave by smoothed particle hydrodynamics (SPH) method. The kinematic behavior of floating debris carried by tsunami waves was numerically simulated. The movement characteristics of floating debris under different conditions were discussed. This research shows that the adopted SPH model can simulate dam-break waves with high accuracy and reliability. The movement behavior of floating debris in dam-break waves is reasonably simulated. For wet bed condition, it is found that the relative velocity of the cylindrical floating debris decreases with the increase of relative density of floating debris, especially for floating debris with large radius. A greater horizontal velocity of the incoming dam-break wave would lead to a higher relative movement velocity of floating debris. For dry bed condition, the velocity and acceleration of the cylindrical floating debris with low relative density would be higher. This research supplies deeper understanding to the kinetic behavior of floating debris in the tsunami waves, and provides important theoretical support for preventing floating debris from impacting nearshore engineering structures.