The electric wheelchair is one of the tools for providing mobility for the elderly and handicapped. However, it is sometimes necessary to practice the operation at a rehabilitation center, etc. in order to be able to use an electric wheelchair effectively. With this sort of background, electric wheelchair operability and drive stability are a problem. For example, it is impossible to cope with changes in the driving environment such as slopes crossing transverse to the direction of travel. Up to now, research and development efforts have been, aimed at attaching new mechanisms to the electric wheelchair to solve these problems. However, there has been a few report made using the control engineering approach. Rather than using construction, or hardware, research and development using control engineering, or software approach, methodology shows strong hope for improving electric wheelchair operability and drive stability. The goal of this research is to improve electric wheelchair drive stability through the development of a control algorithm. In this report, the applicability of the electric wheelchair control system dynamic analysis is confirmed by experiment. A more stable control algorithm based on the drive control experiments is also considered.