Abstract: Robot self-localization is realized by using adaptive particle filter scheme with map-matching algorithm. A two-phase-updating method based on similarity measurements of range and geometry is proposed to improve the performance of general particle filter localization which uses a laser range finder. The algorithm not only enhances the robustness of the system, but also increases the computational effciency. Simulation results demonstrate that by using the proposed algorithm and nature characteristics in indoor environment, mobile robot can localize itself accurately androbustly.