In this paper, a novel variable structure control algorithm, named predictive variable structure(PVS) control, is designed for a brushless DC motor servo system to track a given referred position signal. The PVS control strategy is described in detail based on phase plane analysis, and exponential stability of the controlled closed-loop system is proved. Since in this novel control strategy no sliding mode is constructed, the chattering in conventional sliding mode variable structure control method can be eliminated. Moreover, this control strategy can avoid overshoot and is computational efficient. Experiment results demonstrate that the control method improve dynamic and static performances of brushless DC motor servo control systems.