We studied collision between a fluid surface and a rigid disk using smoothed particle hydrodynamics (SPH) technique. Analytical treatment of the problem is extreamely difficult because the free surface of the fluid largely deforms. SPH is an effective method to solve such problems which involve time-dependent boundary condition. In our model, a collision between the disk and the fluid surface is characterized by Reynolds number, Froude number, angle of incidence of the colliding disk and the ratio of disk density to fluid density. For oblique impact, the disk will go down into fluid or rebound. We numerically investigated the conditions for the rebounds.