Abstract: To deal with the localization and mapping problem of miniature robot equipped with monocular camera and encoders,an SLAM(simultaneous localization and mapping) approach based on particle filtering is presented.The image features are detected from camera and matched among successive frames,and then coordinates of the corresponding features in environments are computed according to the camera poses.The rough estimates of robot poses are obtained from the encoder motion model.During robot motion,the information from feature observations is fused with that from the encoders by particle filter,so location precision of the robot is improved and also more exact coordinates of the features are gotten.The reliability and efficiency of the method are proved by simulation experiments.