Aiming at realization of direct and intuitive cooperation between human and robot, we propose an interface system for a two-wheeled, autonomous mobile robot that can take physical communication with its user via haptic, or hand-tohand force interaction. The hand-shaped device equipped on the robot has 1 DOF at the finger part and is capable of gently grasping a human hand when actuated. The force information is acquired by using strain gages on the flexible, rubber-made arm that physically supports the hand. The robot's motion is determined by the force input and/or the environmental condition. The robot recognizes obstacles by using bumper sensors and ultrasonic sensors around the body. When it touches an obstacle, the robot changes the route regardless of the user's intentional force and thus informs the user of such situation of obstacle avoidance. In this research, we design simple algorithms for both human-following and human-leading motions, and devise experiments with...