This paper presents the speed tracking control of unicycle type mobile robot in the presence of environmental disturbances and model uncertainties. In order to solve tracking issues, a Linear Active Disturbance Rejection Control (LADRC) based control is proposed here. the forces and voltages of the motors acting on the two wheels are considered in the dynamic model of the robot. The proposed control strategy doesn't require either the precise information about the plant model or a model of the disturbances since it is based on the real-time estimation and compensation of the uncertain dynamics and different environmental effects. Robustness of the control system is discussed here. A simulation and comparison between the LADRC based controller and a well-tuned PI controller have been, and the results confirmed that the LADRC controller has the best robustness and tracking performances.