[Objective] This study was to investigate the allelopathic effects of J.curcas leaf leachates on seedling growth and antioxidative enzymes,and thus to reveal physiologically allelopathic effects of J.curcas trees on undergrowth plants.[Method] The allelopathic effects of leaf leachates of Jatropha curcas amended into soil were determined on the growth,proline and malondialdehyde（MDA） contentas well as superoxide dismutase（SOD）,catalase（CAT）,ascorbate peroxidase（APX）,guaiacol peroxidase（POD） in roots of marigold（Tagetes erecta） seedlings.[Results] The application of leaf leachates of J.curcas in the soil significantly inhibited the shoot and root length of marigold compared to un-amended soils.The leaf leachates increased the O-2,H2O2,MDA and proline content in the roots of marigold seedlings.The effects increased with the ascending of leaf leachates concentration.In addition,superoxide dismutase（SOD） and guaiacol peroxidase（POD） were not remarkably affected by the leachates at lower concentrations,but at higher concentration,SOD activity was ascended.Similarly,the activities of CAT and APX were also significantly increased with the increase of leachates concentrations.[Conclusion] These results show that J.curcas can release the phytotoxic compound（s） into soil,which are inhibitory to certain test species by interfering with physiological process.
