In this report, I wish to examine the oscillation of floating bodies and the behavior of the mooring system subjected to wind force.
　It is well-known that the properites of wind vary with time and place, however there are some points which are uncertain at the present time, especially in wind above sea. Therefore I analyzed wind data obtained by sonic anemometers at Ohsaka Bay, and studied the fundemental properties of wind above sea.
　I propose a few estimated methods of wind force acted on floating bodies, based on the result of wind observation. I carried out some numerical simulations by computer on three floating body models in order to know the effects by species of power-spectrum of wind, wind distribution, the characteristics of springs and so on.