Environmental problems such as air pollution are worsening due to urbanization. Urban street trees have the advantage of alleviating environmental problems by carrying out air purification. Thus, it is necessary to obtain street tree information for efficient planting and management of trees. In the present study, the i-Tree Eco model was applied to classify street trees according to species and diameter at breast height. The amount of air pollutant removal, carbon storage, carbon sequestration, and oxygen generation by street trees was calculated. The field data of 43,124 street trees in Suwon, Korea, accounting for a total leaf area of 4,422,190 m<sup>2</sup>, including ginkgo, zelkova, and Japanese flowering cherry, were used. The total air pollutants (CO, NO<sub>2</sub>, O<sub>3</sub>, and SO<sub>2</sub>) removed by street trees in Suwon were calculated as 7.93 ton/yr. The carbon storage, sequestration, and oxygen production accompanying plant growth were 4,077, 299, and 797 ton/yr, respectively. Ginkgo was found to have the best efficiency in terms of carbon storage and sequestration, accounting for 30.3% and 31.5% of the total carbon storage and sequestration, respectively.