To study the reasons for dormancy and characteristics of endogenous inhibitory substances of Paris polyphylla var. yunnanensis, seed germination, seedlings growth and antioxidant enzymes of three kinds of crops in different concentrations of we studied the methanol extract from P. polyphylla var. yunnanensis seed coat and endosperm in order to investigate the relationship between the restraining substraces in seed coat and endosperm in dormancy of P. polyphylla var. yunnanensis Hope to provide scientific reference for breaking P. polyphylla var. yunnanensis seed dormancy. The results showed that: (1) there are endogenous inhibitory both in seed coat and endosperm, and the inhibitory action from endosperm is stronger than that of seed coat. (2) Three receptor plant seedlings show different sensibility to the endogenous inhibitory of seed coat and endosperm, Brassica campestris L. ssp. pekinensis (Oil) seeds are significantly more sensitive than Triticum aestivum (Starch) seeds and Vigna radiata (Protein) seeds. (3) Inhibition by P. polyphylla var. yunnanensis seed coat and endosperm methanol extraction, the strength of growth indexes about seed germination and seedling are rating as: germination rate >seedling root length >seedling height> fresh weight.(4)The inhibitory substances in the seed coat and endosperm cause the physiological response of the three receptor plant seedlings, and start the antioxidant enzyme system. With the increase of seed coat methanol extract concentration， the activities of superoxide dismutase(SOD) and peroxidase(Pod) increased first and then decreased, while catalase(CAT) activity continued to decline. After treatment with methanol extract from endosperm, the activities of SOD and POD were significantly increased compared with control group, and CAT activity decreased significantly. The study found that there are chemical components both in seed coat and endosperm of P. polyphylla var. yunnanensis，These chemicals inhibited the seed germination and seedling growth of recipient plants, affected the activities of antioxidant enzymes in seedlings. However, there were differences in the activity of the inhibitors contained in seed coat and endosperm.