Giant magnetostrictive actuator (GMA) has been used in precise position, active vibration control etc. for its merits of large output force and displacement. At low drive level, GMA presents linear relation between displacement and input current, while nonlinear appears when applied moderate or high drive level. This paper addresses the development of model-based adaptive sliding mode control designs for GMA operating in nonlinear and hysteretic regimes. Homogenized energy model in combination with a quadratic moment rotation model for magnetostriction is adopted in this paper to describe hysteresis of GMA, and its inverse model is employed as a inverse filter before GMA system to compensate the hysteresis and nonlinear. The proposed control law guaranteed global stability of the control system with certain accuracy in tracking desired trajectories. Simulation result verified the correctness and effectiveness of the extracted control method.