Abstract:In order to explore different water adaptation capacity of Jatropha curcas L., we investigated changes of the plant in growth, physiological and biochemical characteristics after 3 month experiment. Seedlings were subjected to 3 watering regimes which were watered to 80%, 50%and 30% field capacity (FC), respectively. Companying with decrease of soil water content, significant decreases in height, biomass accumulation, transpiration rate and stomatal conductance, and increases in leaf/area ratio, biomass accumulation and the content of pigments were detected at the end of experiment. However, there was no significant difference in root/shoot ratio, root/weight ratio, specific leaf area, net photosynthesis rate and maximal quantum yield of PS II. In addition, the content of malondialdehyde, hydrogen peroxide (H2O2), soluble sugar, free proline and ascorbic acid, and activity of superoxide dismutase were highest under 80% FC. The results suggested that J. curcas, as a drought tolerance species, could decrease water losing by closing stoma and decreasing transpiration rate, and therefore 30% FC were not caused drought stress to it. However, excessive water supply (80% FC) was not the optimum condition for its physiological metabolize due to the accumulation of H2O2, aggravation membrane lipid peroxidation and the degradation of chlorophyll. So we think that under the local soil nutrient condition 30%-50% FC is the optimum soil moisture content for J. curcas.