This paper describes the development of driver model in electric wheelchair operation. Existing methods have problems: to improve wheelchair adjustment, it takes a lot of trial and error and, so burdens users. Thus, in this study, we proposed simulation solutions. Simulations for improvement need three models: surroundings, driver and vehicle. Existing researches allow us to make surroundings and vehicle models, but not driver models which are suitable for the simulations. To make the model, we figured out the operation property using an electric wheelchair simulator. First, we carried out many experiments on able-bodied persons and made the common forms of the driver model. Then, we carried out a small number of experiments on a person with severe disabilities and fixed the model.