Abstract: Thirty tree species commonly planted for afforestation in the northern plain area of Zhejiang Province were taken as study objects, the diurnal variation in photosynthesis and the photosynthetic response to different light intensity of these tree species were measured with Li-6400 portable photosynthesis device. The diurnal variation curves of the photosynthesis, carbon sequestration and oxygen release capacity, light response curves and photosynthetic physiological parameters of the thirty tree species were analyzed. The results showed that carbon accumulation mainly took place in the morning, and more carbon could be accumulated via metabolism by the tree species with stronger photosynthesis capacity. The study indicated that Cinnamonum campora had maximum carbon fixation and oxygen release (3231340mmol/(m2·s)), followed by Amygdalus persica var. persica, Salix babylonica, Lithocarpus glabra, and the least amount of carbon fixation and oxygen release happened to Prunus cerasifera f. atropurpurea (61.8644mmol/(m2·s)). The light response curves and photosynthetic indexes of Cinnamonum campora, Salix babylonica, Amygdalus persica var. persica, and Albizia julibrissin showed that these tree species had stronger adaptability to local site conditions. The comprehensive analyses showed that Cinnamonum campora, Amygdalus persica var. persica, Salix babylonica,Albizia julibrissin, Sapindus mukorossi, Lithocarpus glabra, Acer buergerianum and Ligustrum lucidum should be selected to be planted with priority in the northern plain area of Zhejiang Province for their stronger capacity of carbon sequestration.