In order to evaluate the urban green transportation development objectively, according to the comprehensive consideration of green transportation concept and connotation, this paper selects some indicators and establishes a green transportation evaluation index system from the three aspects of transportation infrastructure, public transportation service quality and environmental impact, and uses a combination of PCA and entropy weight method to obtain the comprehensive weights of the index. Grey relational degree model and cloud matterelement model are adopted to study the development level of green transportation in Nanjing as an example. In addition, gray relational degree clustering is combined for making a comparison about evaluation results. The case analysis indicates that the results of combination of two models have high rationality and consistency. The combination of models could also take both quantitative and qualitative analysis into consideration, which may reflect the development level of urban green transportation more comprehensively.