Abstract: A self-localization system based on near-infrared vision and bar-coded landmarks for robot navigating in out-door environment with variable light conditions and electromagnetic interference is presented.The near-infrared illuminator and omni-directional vision are used for recognizing bar-coded landmarks.Data from vision system and odometry are fused with an extended Kalman filter(EKF) to realize robot self-localization.The experiment result demonstrates that the proposed method eliminates the effect of light variations on robot localization in outdoor long-range navigation.