Abstract: The resistance and motion characteristics of trimaran hull form have been studied by experimental method.The model experiment consists of two parts: the resistance experiment on calm water and the motion experiment in regular waves.According to the experimental data,it can be found that the longitudinal arrangement of the side-hulls plays an important role in trimaran resistance and motion characteristics.For high speed range,the trimaran resistance and motion performance could be significantly improved by placing the side-hulls before the mid-ship of the main hull.Based on the experimental results,a new ship type known as fore-body trimaran i s presented.