Urban street trees are of great significance to the sustainable development of human settlements, and are key factors to enhance the service value of the urban environmental ecosystem. In this regard, it is necessary to improve and balance the benefit distribution of urban street trees for promoting the environmental quality of cities. In order to make clear the urban street tree benefits in a city, this paper presents the study on the ecosystem services from street trees in Shengjing Historical and Cultural Block (SHCB), Shenyang, China. By conducting a field survey on 1968 street trees and using the i-Tree model and the ENVI-met model to quantify the original data, this paper evaluated the ecosystem services distribution of eight streets and nine zones in the SHCB. The results showed that the co-creation annual ecological benefit and annual thermal comfort benefit of the street trees of SHCB were 163,965.62 and 233,533.48 dollars, respectively, totaling 397,499.10 dollars. It is obvious that the thermal comfort benefit is higher than the ecological benefit. Meanwhile, urban streets with high ecological benefit may not necessarily produce high thermal comfort benefit. Therefore, on the basis of ecological benefit analysis, the ecosystem services can be reflected more accurately by superimposing the thermal comfort benefit. The quantitative assessment system obtained in this study can provide a reference for future block planning and urban street tree allocation of SHCB and other regions in similar areas.