Abstract: To better understand the photosynthetic characteristics of Melia azedarach L. clones, investigations were made on leaf photosynthetic parameters of five different clones. Leaf net photosynthetic rate(Pn), stomatal conductance(Gs), leaf transpiration rate(Tr)and intercellular CO₂ concentrations (Ci) were measured by using a portable Licor 6400 photosynthesis system (LI-6400) and then further analysed. The results showed that intercellular CO₂ concentrations (Ci) and physiological water-use efficiencies (WUE) of the five different clones exhibited highly significant differences. Leaf net photosynthetic rate(Pn)and leaf transportation rate(Tr)showed significant differences while stomatal conductances(Gs)of the five clones non-significant. Among them, the three clones, J104 (‘Jiangsu 104’)、J7 (‘Jiangsu 7’) and J61 (‘Jiangsu 61’) had a relatively higher net photosynthetic rate than other clones. Moreover, J61 had a higher water-use efficiencies(WUE).