A robust parameter-optimal iterative learning control algorithm is presented for a class of discrete time nonlinear dynamic system with disturbances. The proposed algorithm has the property of robust BIBO stability of closed loop system, and the system output can monotonously converge to the neighbor domain of desired trajectories in the presence of state, output disturbances and initial uncertainties. In the absence of these disturbances, the system output can converge to desired
trajectories with zero steady-state error. Finally, simulation analysis illustrates the effectiveness of the proposed algorithm.