In order to improve the robustness of missile guidance system to target maneuvering in the terminal guidance phase, a fuzzy variable structure guidance law was designed based on the variable structure control principle.Firstly, a variable structure guidance law was deduced through the theory of variable structure control.Then, the ideal guidance law parameters were found through simulations to reduce the chattering of guidance and enhance its robustness to target maneuvering. Moreover, the parameters of the guidance law were adjusted according to the target maneuver estimation by means of fuzzy control.At last, the designed terminal guidance law was compared with the traditional variable structure and proportional navigation guidance law. The simulation results show that designed guidance law has stronger robustness to target maneuvering.