This paper presents new feedback force rendering scheme for the bilateral teleoperation of mobile robot. Previous research indicated that the feedback force based on obstacle range information prevented accurate motion control of the mobile robot since human operator's commands were distorted by the feedback force. To solve this problem, a new force rendering approach with variable feedback gain is proposed. In proposed scheme, force feedback gain is adaptively tuned based on measured distances to the obstacle and time derivatives of the distances. Stability of the proposed bilateral teleoperation architecture was analyzed and the performance is proved by simulations. Results of simulation and experimental study proved that the quality of the mobile robot bilateral teleoperation with variable force feedback gain is significantly better than the conventional approach with constant feedback gain.