The effects of aqueous extracts from different parts of hot pepper were determined by means of bioassay in laboratory.The results showed that the influences of aqueous extracts of hot pepper on seed germination of hot pepper and tomato were different with different donor parts,concentrations and receptors,and the aqueous extracts from hot pepper had autotoxicity on seed germination of hot pepper and tomato.The seed germination of hot pepper and tomato was inhibited by aqueous extracts from whole plant,root,stem and leaf of hot pepper.With increasing concentration of aqueous extracts,the inhibiting effects on vegetable seed germination expressed strong,which indicates that the aqueous extracts have strong autotoxic effects on seed germination of pepper and tomato.The autotoxic effect order of aqueous extracts from different parts of hot pepper on seed germination of hot pepper was leafrootstemplant,and autotoxic effect order of aqueous extracts from different parts of hot pepper on tomato seed germination was leafplantrootstem,and which indicates that the autotoxic effect of leaf aqueous extract was the strongest.