Abstract: This paper is concernedwiththe theoryof intelligenttransportation system(ITS), and focused on itsmain structure and research contents. In seeking the way to build an ITS structural model, peoples, vehicles, roads and environments are organically united by a technique group to be a traffic system, which runs in good order. So that the traffic efficiency and the traffic safety can be ensured to a great extent, and the environment quality and the energy utilization rate can be improved.