Electric vehicles are no longer an unreachable dream, a vast amount of electric vehicles have gradually appear on the market recently. To charge the batteries of electric vehicles, constructing of charging station is needed. However, due to the conductors and transformers capacities in feeders, not all the power capacity can be allocated to one parking lot. To improve the balance between the power providers and consumers on power grid, charging schedule is required. This paper developed a simulation environment which can achieve charging schedule more efficiently through Particle Swarm Optimization. Moreover, the developed system can verify the voltage profile of the distribution system as well as the conductors and transformer constraints. The simulation results show that the schedule obtained through Particle Swarm Optimization can minimize the charging time under the power constraints.