This paper presents an autonomous wheelchair system with the capability of self-localization. In our system, the ceiling lights are chosen as landmarks to realize the self-localization and auto-navigation of the wheelchair. An approach to landmark recognition is described, and a technique of self-localization for the wheelchair is proposed. Subsequently, the path planning for navigation is discussed. Finally, the total system for our wheelchair is introduced, and a navigation experiment is described. Experimental results indicate the effectiveness of our system.