Abstract
In recent years, the floating facilities for the ocean space utilization such as the marine disaster prevention base and the floating restaurant are planned and some of those facilities are actually built. Most of these facilities are the pontoon type floating structure, and the mooring system is a mooring dolphin. In the design of such facilities, the forecast of the movement of the pontoon type floating structure supported by the mooring dolphin is important. In this research, the 3D-MPS method is applied, and the solitary wave and the bore like wave are applied as an assumed tsunami. The heaving motion on floating body in the tsunami is paid to attention, and it reports on the result of examining the detaching from mooring dolphin of floating body.