Abstract: A new visual dead reckoning positioning method is presented for mobile robot,which is based on lines and single feature points.A camera,whose optical direction is adjusted to be perpendicular to the ceiling,is fixed on the mobile robot.Two intersecting lines in the images of the ceiling and their intersection are extracted as features,the orientation of the mobile robot is estimated based on the orientation of the lines,and then the position of the mobile robot is computed according to the variations of the image coordinates of the intersection pixels.When the mobile robot moves,the intersection may be nearing to the margin of the image,and at this time a new intersection will be selected to replace the old one as the new feature point.The results of positioning experiments in indoor environment verify the effectiveness of the proposed method.