Abstract: In this paper, the i-Tree Model was applied to analyze the composition of the street trees in Shinan District of Qingdao, and to quantify the economic value of the street trees’ ecological benefits in storm water interception, CO₂ absorption and sequestration, air quality improvement, and energy saving in 2012. On the main roads of the District, there were 12322 individuals of 43 street tree species, among which, the top 10 species such as Platanus spp. and Ginkgo biloba accounted for 84.4% of the total. Mediumsized (DBH: 15-30 cm) and smallsized (DBH<15 cm) trees dominated the street trees, occupying 53.54% and 29.06%, respectively. Overall, the street trees were in good health condition, and the healthy trees occupied 97.4% of the total. The annual economic value of the street trees’ ecological benefits was 23032 thousand yuan, and the weighted average benefit of an individual tree was 1869 yuan. This study could offer helpful and scientific references on the planning and planting of urban street trees and the management of urban landscape.

Key words: watermelon, growth index, physiological response., genotype, drought tolerance