Abstract: Jatropha curcas is the most promising energy tree, and soil moisture is the key factor which affects the seedling quality and water use efficiency of J. curcas. With aims to evaluate the effect of different irrigation amount on growth, morphological characteristics and water use of J. curcas, a pot experiment was conducted with four irrigation amounts, i.e., W₁：472.49 mm, W₂：228.79 mm, W₃：154.18 mm and W₄：106.93 mm, respectively. Compared with W₁ treatment, the leaf area and stem crosssection area of base significantly decreased in W₂, W₃ and W₄ treatments, but Huber value significantly increased, which could improve the efficiency of water transfer from root to shoot, thus enhance the capability of resistance to drought stress. Compared with W₁ treatment, the healthy index of J. curcas seedlings decreased slightly in W₂ treatment but significantly decreased in W₃ and W₄ treatments. Hence, the irrigation amount from 228.79 to 472.49 mm was beneficial to increase the healthy index of J. curcas seedlings. Compared with W₁ treatment, irrigation water was saved by 67.4% in W₃ treatment, and the total dry mass and evapotranspiration significantly decreased by 17.4% and 68.6%, and the irrigation water use efficiency and total water use efficiency increased by 153.2% and 163.2%, respectively. In the condition of this study, the irrigation amount of 154.18 mm was beneficial to increase water use efficiency.