Abstract—This work presents an adaptive optimal control algorithm-based integral sliding mode control law for a class of continuous-time systems with input disturbance or uncertain and unknown parameters. The primary objective is to find a general form of integral sliding mode control law can assure that the system states are forced to reach a sliding surface in a finite time. Then, an adaptive optimal control based on the adaptive dynamic programming method is responsible for the robust stability of the closed-loop system. Finally, the theoretical analysis and simulation results demonstrate the performance of the proposed algorithm for an inverted pendulum system.