Abstract
Designers embody one's idea by drawing lots of sketches at the early stage of the design process. Characteristic lines are one of the most important factors that express a feature of the product appearances. Therefore, it can be said that the concretization of characteristic lines is extremely important operation in the design processes. Designers repeatedly draw profile and characteristic lines in the process of sophisticating product images. Therefore, making 3D CAD systems having the function to quickly create and easily adjust the characteristic lines becomes strong support for the style design. The objective of research is to develop a 3D CAD system that can create surfaces with the characteristic lines by easy operations and modify the shapes by changing the parameters defining the lines.
