Abstract: Sixteen species of roadside greening tree in Kunming City were selected for study.The net photosynthetic rate and leaf area index of tested trees were observed.and the capacity of carbon fixation and oxygen capacity was estimated quantitatively by clustering analysis.The results showed that the carbon content per unit area of the 16 commonly used green plants was 5.47-12.32 g /(m²·d), and the oxygen release was 3.98-8.96 g /(m²·d); The carbon content of the land area is 22.11-174.03 g /(m²·d), the release oxygen content is 16.09-126.63 g /(m²·d), the carbon storage capacity of single plant was 2.82-233.02 kg in autumn.The oxygen released in autumn was 1.88-169.55 kg.Magnolia grandiflora, Cinnamomum glanduliferum, Celtis kunmingensis autumn carbon fixation and oxygen release ranked first in the top three.The affiliated leaf area of trees and shrubs was divided into 3 levels of carbon fixation and oxygen release capacity; the arable and carbon releasing capacity of arbors per unit area was divided into 2 grades, and the shrubs were divided into 3 grades, among which the efficiency of carbon fixation and oxygen release of trees was higher than that of shrubs.Therefore, Magnolia grandiflora and Cinnamomum glanduliferum are the main road greening trees, and the road greening mode supplemented by shrubs like Ligustrum quihoui, Camellia japomica, Loropetalum chinense, and other shrubs is more suitable for road greening in Kunming.