By adopting communication, coordination and corporation between agents, multi-agent technology can express complex system and especially can be used to model urban traffic system. Based on the analysis of the characters of multi-agent technology and urban traffic system, application status are summarized from the urban traffic management system, traveler information system and public transportation system. The most representative applications of all areas are also introduced and analyzed. Study shows that multi-agent technology provides effective solutions for urban traffic problems, and it is suggested that in order to make a better use of multi-agent technology, traffic environment and activities need to be modeled correctly. Communication needs to be reduced. Computational and coordination complexity need to be cut down. System stability and security need to be strengthened. Further applications and research directions are also discussed in detail.