Abstract: This paper aims to provide an application basis for good street trees in Xi’an. Through field investigation and information consultation, 20 kinds of main street tree species in Xi’an were determined. Using the method of AHP, comprehensive evaluation of trees was done with 15 indexes, including the green period, view the flowers, leaf ornamental value, fruit ornamental value, lush foliage, maintenance difficulty, planting survival rate, resistance to pruning, cold resistance, drought resistance, barren resistance, disease and pest resistance, anti pollution ability, dust removal ability, and noise reduction ability. According to the evaluation results, the authors recommended the trees according to 3 levels, the number of first level trees was 10, that of the second level was 6, and that of the third level was 4. The fist level was a priority in romoting street trees, followed by the second level, the third level was the last.