The characteristic of the electric vehicle（EV）power is summarized.The Monte Carlo method is used to simulate the charging and discharging behaviors of EVs，and the load characteristic curves of plug-in EVs of different scales are obtained.The demand characteristic of uncoordinated charging EVs and the capacity curve of controlled charging and discharging EVs in the vehicle-to-grid（V2G）mode are analyzed.Then the multi-objective economical dispatch model for microgrid considering plug-in EVs is developed.Take the one-day economical dispatch of a certain area，which shows the optimal dispatch results of different strategies and different objective functions are obtained with the priority list based on the software package of Visual C++.Finally，the availability and feasibility of the model are verified through a comparative analysis.