In this paper,computational models of environmental pollution and energy consumption of urban multimodal traffic network are proposed according to pertinent research and a multi-objective programming model is then developed to formulate optimization problem for such a system.Simultaneously,the main factors,such as travel time,pricing and convenience which influence travelers’ choice behaviors are all considered and a combined assignment model is proposed to simulate travelers’ mode and route choices.A bi-level programming model,in which the multi-objective optimization model is treated as the upper-level problem and the combined assignment model is processed as the lower-level problem,is then presented to solve multi-criterion system optimization problem for urban multimodal traffic network.The solution algorithms of the proposed models are also presented.Finally,the model and its algorithms are illustrated through a simple numerical example. In this paper, computational models of environmental pollution and energy consumption of urban multimodal traffic networks are proposed according pertinent research and a multi-objective programming model then then to formulate optimization problem for such a system. Simultaneously, the main factors, such as travel time, pricing and convenience which influence travelers ’choice behaviors are all considered and a combined assignment model is proposed to simulate travelers’ mode and route choices. A bi-level programming model, in which the multi-objective optimization model is treated as the upper-level problem and the combined assignment model is processed as the lower-level problem, is then presented to solve multi-criterion system optimization problem for urban multimodal traffic network. The solution algorithms of the proposed models are also presented .Finally, the model and its algorithms are illustrated through a simple numerical example.