This paper based on analyzing the effect of the component of the plant community and ecological factor, such as: soil, illumination and etc., upon the structure and function of urban plant community, probing into the configuration regularity of urban plant community. Result shows: the component and forest phase of the urban plant community still has a feature of zonal vegetation although it is influence by people activity; The habitat made by upper stratum effect on under plants distribution in plant community, under plant species is diversity. The result of factor analysis shows: the relatedness exists between structure factors of plant community, four factors contain 85%of information content: canopy, average high of arborous layer, density of arborous layer and underbrush character. The soil factor correlate with the height growth and density of the community; The species component, density and index of crown cover in the tree layer effect on distribution of illumination and under plants in the plant community. Analyzing shows: the landscape of the community is most correlative to the structure, the broad-leaf mixed forest has a most landscape effect in Shanghai.