Motor vehicles bring the stern challenge to development of automobile industry and ecological environment. In China the present quantity of motor vehicle in use is 1/43 in America and 1/12 in Japan. Since the legislation and control technology on exhaust emssion is still not stringent and consummate, motor vehicle emissions have constituted a public health hazard in China metropolitan areas, especially in Shanghai with its population over 10 million and complicated road distribution.The author describes the inspection program of pollutant situation on major crossings in Shanghai, the study of exhaust emission in various types of motor vehicle. Based on which the reasons for vehicle pollution in Shanghai, the effect of the automobile on the urban environment and the public health, are analysed, the contribution rate of vehicle emission toward Shanghai air enviroment pollution in 1989 is estimated. Also, countermeasures are put forward which will be helpful to other developing countries.