This paper proposed an on-line reference governor for a mobile robot with velocity feedback controller. In order to follow given time path by a mobile robot, it is a practical subject how to cope with the disturbances by the slippage and the restrictions on the control system. In this paper, we proposed a methodology to adjust iteratively the control reference based on time scaling approach for a mobile robot to follow the path. By introducing proposed on-line reference governor, control input saturation can be reduced in case of that the disturbances occur during traveling and path tracking error is also reduced. For verification of our proposed method, computer simulations utilizing a plant with stable feedback controller were conducted and the results were discussed in this paper.