Abstract: The effect on photosynthetic characters of Liriodendron chinense from Zhejiang province under different waterlogging time stress was studied. After 2 h waterlogging treatment, the stomata conductance, the net photosynthetic rate (Pn) and the transpiration rate increased a little, but decreased markedly after 24 h waterlogging treatment, and decreased to the least after 48 h waterlogging treatment. The results showed that the longer the stress time, the more serious the restraint to photosynthesis and the transpiration. But the different results occurred for intercellular CO2 concentration (increased obviously after 48 h waterlogging treatment). The coefficient analysis indicated that, between Pn and the stomata conductance, between the transpiration rate and the stomata conductance, there was an obvious positive correlation.