The sway control problem of the pendulum motion of the container crane hanging on the trolley, which transports containers from the container ship to the truck, is considered in this paper. in the container crane control problem, the main issue is to suppress the residual swing motion of the container at the end of the acceleration, deceleration or the case of that the unexpected disturbance input exists. For this problem, in general, the trolley motion control strategy is introduced and applied to real plants. in this paper, we consider a mass damper type of swing motion control system for a crane in which a small auxiliary mass is installed on the spreader. The actuator reacting against the auxiliary mass applies inertial control forces to the spreader of the container crane to reduce the swing motion in the desired manner. in this paper, we consider that the length of the rope is varied in the specified range and we design the anti-sway control system based on gain-scheduling approach. And, we investigate usefulness of the proposed antisway system and evaluate system performance from experimental study.