An automatic guiding system for analyzing ground texture in or on an autonomous mobile device comprises an image acquisition module, a ground texture analysis module, a posture sensing module, and a ground texture database. The image acquisition module collects ground images as the autonomous mobile device moves. The ground texture analysis module processes the ground images, and extracts texture information of the ground images. The posture sensing module continuously senses the posture of the autonomous mobile device. The ground texture database is configured to stores the texture information and the posture.