A simulation analysis has been conducted to simulate the rapid change of velocity and water depth in amenity oriented river by short time heavy rainfall. The model used here comprises the runoff model by the kinematic wave model, the 1-D unsteady flow model by the dynamic wave model and the 2-D inundation flow model by the generalized curvilinear coordinate system. The Kamo river in Kyoto city, Japan was studied based on the recently observed rainfall. Through the analysis, it was found that some river sites in the Kamo river including Hiragino park: area become dangerous by the short time heavy rainfall. Also, with respect to the maximum velocity and water depth and their rate of change, flood hazard is discussed, and a flood hazard of river recreational site can be presented on the map.