A novel fuzzy based control law for the trajectory tracking design of nonholonomic mobile robots is presented in this paper. This approach can be applied to generate trajectory tracking control commands on nonholonomic mobile robot movement. The design objective is to specify one fuzzy control law that can force the mobile robot to follow a predefined trajectory for the nonlinear trajectory tracking control of nonholonomic mobile robot. In general, it is hard to obtain the closed-form solution from this nonlinear trajectory-tracking problem hence we try to treat this trajectory tracking problem from the so-called fuzzy control design concepts. Finally, one testing condition: circular reference trajectory is used for performance verifications.