Suspension design is one of many important disciplines required to develop automobiles. Since a suspension system has strong non-linearities and many design variables, it is difficult to design. In this paper, the authors discuss the benefits of an optimization technique to design suspension systems and propose a design support system based on the concepts of optimization, Response Surface Methodology (RSM), and consideration of robust design techniques. A prototype of the design support system for automobile suspension design was developed. In this system, the suspension was analyzed and evaluated by the mechanical system simulation software ADAMS. The validity of the design support system was clarified through case studies by focusing on toe characteristics. The design technique using the proposed design support system is discussed.