Abstract:In this paper, thirty common highway afforestation tree species in southern Jiangsu province were selected as the research materials, and a portable Li6400 photosynthesis apparatus is used to measure the responses of photosynthesis to different light intensities and the photosynthetic diurnal variation, furthermore, cluster analysis and factor analysis were used to analyze the daily net carbon sequestration and examine the fitting physiological parameters of photosynthesis of thirty tree species. The results showed that Cinnamonum campora has the highest carbon fixation ((11.957±1.053)g·m-2·d-1 ), followed by Prunus persica Batsch. var. duplex Rehd., Lagerstroemia indica, Sapindus mukorossi,Populus euramevicana,Bambusa multiplex,Magnolia grandiflora, and Celtis sinensis, and Prunus cerasifera var. atropurea has the lowest carbon fixation ((3.888±0.204)g·m-2·d-1).The daily net carbon of sequestration Cinnamonum campora and Prunus cerasifera var. atropurea has extremely significant difference (P<0.01). Sapindus mukorossi,Aucuba japonica and Ginkgo biloba have better growth and adaptability in southern Jiangsu, followed by Cinnamonum campora,Hibiscus syriacus,Prunus persica Batsch. var. duplex Rehd. and et al. so we suggested that Cinnamonum campora,Prunus persica Batsch. var. duplex Rehd., Lagerstroemia indica,Celtis sinensis,Sapindus mukorossi,Bambusa multiplex,Osmanthus fragrans,Ulmus pumila,Armeniaca mume, and Chimonanthus praecox can be preferred in as priority selection are recommended for road carbon sink forests construction in southern Jiangsu.