Monitors the cars in the video frame by background modeling and background difference method with the video-based monitor system of vehicle violation. Establishes the new-coming car information by tracking the existing vehicle and calculate the car's position of next frame. Proceeds to make a judgement on whether the car violates regulations or not by the state of traffic light and the car's present position. Sends an image-capturing signal as the vehicle violates regulations and combines the vehicle's information and the captured HD pictures into a piece of complete violation information. The operation of the system is stable with high robustness and accuracy under any weather or traffic flow volume. Keywords ：veh