Abstract: A graphics support platform for Computer Aided Shipbuilding Integrated System (CASIS) is presented. It provides designers an interactive graphics environment on the concept of product not on the graphics elements of point, line, are, circle etc. An exploration of using a product model in an engineering application is niade and an experimental system, a new type CAD system, is established. The product model of the ship structure is illustrated, on which the platform is created, and the main idea, functions of this platform are described. The strdtegy of application development based on this platform is discussed also.