This paper describes a development of a robot scooter platform for intelligent personal mobility robot. Recently, a lot of personal mobility has been used by aged and handicapped people. Intelligent mobility robot provides safer and more convenient transfer service such as driving support and automatic transfer. It is necessary to develop a platform equipped with sensors, electronic devices and intelligent navigation functions. In this paper, we describe the hardware components and the configuration of the robot platform. The navigation system, including the functions of localization using grid map matching, path following, and obstacle avoidance, is implemented on the proposed robot platform. We also present the results of an open-field experiment in Tsukuba Challenge 2010 and evaluate the proposed systems. The newly developed robot scooter successfully and autonomously ran a 1.1 km course in a normal living environment.