With the variable structure sliding mode control thoery, we define a sliding mode attitude maneuver controller for an underactuated rigid spacecraft. First we introduced and analyzed the three-axis stabilized underactuated spacecraft attitude dynamics and kinematics models, based on the model characteristics we design a asymptotic stability sliding mode control law and give the proof of global asymptotic stability in Lyapunov’s sense. The simulation results show that the method can effectively achieve underactuated spacecraft attitude control and get global stability and robustness.