Abstract: Optimization of the structure of passenger transportation is considered as one of effective ways for sustainable development of urban transport systems.It plays an important role in improving efficiency of urban transport systems for passengers.A fuzzy interpretive structural model is developed based on characteristics of influencing factors, and divides them into four levels which including direct influencing perceptional layer, indirect influencing cognitive factor layer, transitional connection factor layer, and fundamental factor layer.Meanwhile, inter-layer and intra-layer influencing factors are connected by the directional arc.The modeling results show that urban scale of the passenger traffic structure is the fundamental factor;capital investment is the transitional connection factor;and road layout, infrastructure, and characteristics of passengers are the indirect influencing cognitive factors.The urban transport systems in Harbin are taken as a case study.The results of this study determines key factors for optimizing structure of passenger transportation, and puts forward suggestions on optimization of urban transport systems for passengers from the aspects of traffic policy, land use, and travel modes.