Abstract: Light rail traffic is becoming a favored city traffic system because of its less pollution to environment, saving energy, less investment, quick benefit and big freight volume. The technologies of urban light rail vehicles are developing quickly. In this paper, the development of urban light rail vehicles is discussed in detail from the aspects of car-body, running gear and electric drive system, which involves the technologies of low floor, independent wheels and IGBT,etc. Meanwhile, the present application of light rail vehicles overseas is briefly introduced, and the future developing trend of light rail vehicles in cities is analyzed.