Abstract: With the high speed development of China's renewable energy, uncertainty of the grid promotes the increasing of storage capacity. Based on the China-TIMES model and electric car's peak shaving model, this research analyzed the carbon emission of energy system under the impact of vehicle-to-grid technology with different penetration rate. It proposed to use Monte Carlo simulation to extract the state of charge and charging period. And it calculated the shaving capacity of electric cars by classification of different state of electric cars. Then it obtained the peak shaving capacity by hour. The analysis and calculation results show that:the electric vehicle energy storage technology has the ability to reduce the difference between peak and valley. Besides, V2G technology can ease the pressure of carbon emission of China and it will contribute significantly to the goal of carbon emission.