In this paper, new force feedback rendering scheme for mobile robot teleoperation is presented. Previous research indicated the problem of the low quality of mobile robot's motion control during the teleoperation with feedback force based on obstacle range information. Human-operator's commands were distorted by the feedback force, as a result, mobile robot could not follow human-operator's intention. To solve this problem, a new force rendering approach with variable feedback gain is proposed. Force feedback gain is variable based on measured distances to the obstacle and derivatives of the distances. Simulation and experimental study showed that the variable haptic feedback improves the quality of mobile robot teleoperation. variable feedback force improved the quality of mobile robot teleoperation by making robot's trajectory smooth and accurate.