Research on the interactions between fluid and structures has been conducted worldwide. However, the analysis of dynamic structure interacting with the fluid is mostly dependent on experiments and takes a lot of time and cost. In this study, the incompressible smoothed particle hydrodynamics(ISPH) method is used for the analysis of interaction between fluid and a floating body In order to verify the dynamic behavior of fluid with free surface, results are compared with ABAQUS and experiments. In addition, a free falling simulation of a body is compared with experiment.