On the basis of calculating the ranking of urban traffic green development level，this report divides 38 major cities into three categories：high，medium and low traffic “green” degree. And analysis the reasons for the green development of three types of urban traffic from five aspects：economic basis，government financial situation，government management efficiency，urban population growth rate and residents’ travel habits. Generally speaking，the degree of urban green development is positively correlated with urban GDP，government revenue，government management efficiency and urban population growth rate. In addition，starting with the development of typical urban traffic，the reasons for the formation of the top five cities and the bottom five cities are analyzed.