Abstract: In order to provide scientific foundation for selection and configuration of urban greening tree species as well as mitigation of urban heat island effect, six main urban evergreen tree species in Shanghai were studied to analyze the effect of carbon sequestration & oxygen release and cooling & humidifying. The Li-6400XT photosynthetic apparatus was employed to illustrate physiological indicators of the six tree species including Cinnamonum campora, Magnolia grandiflora, Osmanthus fragrans, Distylium racemosum, Ilex chinenisis, Cryptomeria fortunei in Shanghai. The measured indicators included the diurnal variation of photosynthesis and transpiration, tridimensional green biomass(TGB), leaf area, leaf area index(LAI)and other morphological parameters. Through the growing season of a year, the capacity of carbon sequestration & oxygen release, cooling & humidifying of each tree was in same sequence from high to low, that is summer > autumn > spring > winter. Regarding the capacity of annual carbon seqestration and oxygen release, the sequence of the six tree species from high to low was C. campora, M. grandiflora, C. fortunei,O. fragrans, I. chinenisis, D. racemosum. And in summer the sequence of carbon seqestration and oxygen release capacity from high to low was I. chinenisis, C. campora, D. racemosum, O. fragrans, M. grandiflora, C. fortunei; the sequence of daily carbon seqestration and oxygen release capacity from high to low was I. chinenisis, C. campora, D. racemosum, O. fragrans, M. grandiflora, C. fortunei. Regarding the capacity of coolingand humidifying of the measured tree species in summer, the sequence from high to low was C. campora, I. chinenisis, O. fragrans, M. grandiflora, D. racemosum, C. fortunei. However, for daily cooling and humidifying capacity, the sequence from high to low was I. chinenisis, D. racemosum, C. campora, M. grandiflora, O. fragrans, C. fortunei. The results suggested that C. campora and M. grandiflora should be taken as the prioity selection for urban greening regarding the capacity of carbon sequestration & oxygen release and cooling & humidifying. The tree species with low capacity of cooling and high aesthetic value, such as C. fortunei, did not suggest to use in a large area. In addition, by combining the morphological factors such as three dimensional green volume, leaf area index, leaf area and optimizing the structure of urban greening trees, the ecological benefits and urban landscaping would be maximization.