Abstract: Sampling method was employed toInvestigate street trees within Second Ring RoadIn Hefei City, the study area covers about 100km2. Based on the field data, the I-Tree software, developed by USDA Forest Service Research, State and Private Forestry, and other cooperators, was run to analyze street trees’ structure and calculate their ecological and economic benefits, which Including stormwater intercepetion, sequestered CO2 from atmosphere, air quality Improvement, aesthetic benifits and CO2 storage. The results showed that there were 16 street tree speciesIn the study area, and total about 38852 Individuals, the 4 species of Cinnamomum campora, Magnolia grandiflora, Platanus acerifolia and Sophora japonica reached 68.7% of street tree population; 94.5% of street tree was evaluated as health, but the health situation of Magnolia grandiflora being named as city tree was lower then average; the proportion of small trees (dbh<15cm) reached to 64.6% of street tree population, they were plantedIn the recent years. Total 51.45 millions of economical benefit the street trees produced annually was accounted, among 89% was from rainfallIntercept by tree canopy; the benefit of C storage of biomass was evaluated as 7.59 millions RMB; The highest value of ecological benefit for anIndividual tree was produced by Platanus acerifolia, then Koelreuteria paniculata, Sophora japonica and Sapium sebiferumIn order., because these 4 species have had more big trees (dbh>30cm). Analysis and understanding of street tree structure was essential for street tree planning, planting and management.