The structure of traffic demand for community bus system in local city is different from for normal traffic mode. Therefore, internal transport demand should be aroused. In the study, a frame of analysis not only considering with level of service but also with variety of characteristic is proposed. A resident in local city is regarded as an agent and an artificial society is constructed concerning with urban transport system with community bus. A characteristic of actual conditions of community bus system in the target area is summarized. A complex structure of decision making is modelling with decition tree method. moreover, emergency from interaction and micromacro relation is observed in artificial society with community bus. Therefore, it is instructive for the transportation policy with community bus.