We present a path planning model of crowd based on Grid-Potential fields. We represent terrain space as a potential field and discretize it into a regular grid. A voltage variable is defined at the center of each grid cell. The moving of crowd is view as the flow from high voltage to low voltage. Our approach unifies global path planning and local collision avoidance into a single framework in our model. Individuals need not to interact on others but perform global path planning to avoid both obstacles and other individuals. In response to emergencies, we also consider the real-time path planning in our model.