Abstract: The large-scale integration of electric vehicles will result in a great impact on the load of power grid. One effective countermeasure is to predict charging load. From the perspective of the electric vehicle motion, by combing with improved parking demand model, a spatial load forecast model of charging demand for large-scale electric vehicles is built based on their motion characteristics. The factors that affect the charging load demands are analyzed from such aspects as car types, start charging time, battery capacity, charging power and so on. Then the Monte Carlo method is used to simulate charging behavior of large-scale electric vehicles in different times and regions. Taking Beijing power grid as an example, the daily load curve in 2030 is predicted. The results show that the accessing of large-scale electric vehicles to power grid will cause a great increase of the load, enlarge the difference between peak and valley load. So a rational planning for power grid and the reasonable allocation of charging load for electric vehicle is needed.