We have developed a path planning and path following system for a mobile robot. First, the point cloud data of the environment are transfered into polygonal expression by giving the vertex using GUI. Considerating the robot size, the planning system calculates the approximated polygons of configuration obstacles in the two dimensional configuration space, and generates the visibility graph and tangential graph. Then, the shortest path between given start and goal point is planned by graph search. We also developped a control program for our experimental mobile robot to follow the planned path. We made experiments of path planning and travelling control in our laboratory.