Abstract: The basic theory of FTA, its analysis process and the introduction of FTA according to the practical problems of urban traffic is discussed． The classification of factors causing  accidents is carried out by  preventing a following car striking a car in front, for example． The evaluation system concerning urban traffic is accomplished and focuses on the development process and function of qualitative analysis， quantitative analysis，intelligent evaluation， etc． The benefits and the prospect of the system were  analyzed. The result promotes the intellectualization and modernization of traffic management．

Key words: fault tree analysis, urban traffic, intelligent evaluation