Because of the strong non-linearity and uncertainty, the dynamics restraints of autopilots, as well as the effects of wave disturbances, designing a high performance ship course controller is always a difficult work. This paper presents a design of the ship course auto disturbance rejection controller (ADRC) based on the nonlinear mathematical model of ship course locomotion with autopilot restrictions and the model of wave disturbances. Simulation results of ship course tracking and keeping show that the controller has good adaptabilities on the system nonlinearity and strong robustness to parameter perturbations of the ship and environmental disturbances.