Leaf photosynthetic parameters of 20 populations of Eulaliopsis binate from 20 counties of 9 provinces such as Guangdong, Guangxi, etc were determined by LI -6400 Photosynthetic Measuring System. The results showed that extremely significant difference in leaf net photosynthetic rate ( Pn), stomatal conductance ( Gs), transpiration rate ( Tr), intercellular CO2 concentration (Ci) and water use efficiency existed among populations, and there were significant corre- lations between the various leaf photosynthetic parameters. 20 population...