In the same planting environment and extracting condition, lectins were extracted from leaf tissues of 6 resistant and susceptible varieties of Ipomoea batatas.The result showed: 6 varieties had highly hemagglutining activity for rabbit's red blood cell. The difference was that the hemagglutining activity and activition peak in between varieties. Moreover, stability of heat treatment, stability of acidity and alkaline, inhibition of hemagglutination of many succharides and bacteriostatic effect of the lect...