Electrical mobile cart,one of low-speed small four-wheel vehicles, is becoming unsubstituted in the aged society recently. As we know, wheel Steering System plays an important role in riding comforts, stability of handling, and safety. The purpose of this study is to develop a systematic design procedure for the steering system of low-speed small four-wheel vehicles. First, to investigate the basic requirements and characteristics of low-speed small four-wheel vehicles. Second, to generalize the essential characteristics and establish the requirement book of steering systems. Third, kinematic design the original steering system by design procedure. Finally, kinematic design the single-A suspension steering system by design procedure.