Abstract: Schima superba was grown in greenhouse. The rate of photosynthesis and leaf conductance appeared to change in parallel in response to change of light intensity in lower photon quantum flux intensity. A photosynthetic rate of 10 μmol m^-2s^-1 was measured at 24 to 26℃ and leaves were light saturated by 0.7mmol m^-2s^-1. The photosynthetic optimum temperature was 24 to 27℃ and photosynthesis decreased more rapidly at leaf temperature above 30℃, which suggests that photosynthesis under field condition may be limited by the high temperature observed in summer.The rate of photosynthesis increases with increasing intercellular CO₂ concentration and the CO₂ compensation point of photosynthesis was with a value 35μl·l^-1.CO₂ exchange in Schima superba was sensitive to change in leaf to air water vapor gradient. The rate of photosynthesis and leaf conductance decreased from 10 to 6.1μmol m^-2s^-1 and 0.12 to 0.05 mol m^-2s^-1, respectively. The decrease in photosynthesis rate was attributable to a decrease in intercellular CO₂ concentration.These results showed that Schima superba is a tropical species with humidity sensitive stomates and this phenomenon is quite common in tropical plants.