Abstract: We have studied the characteristics of peroxidase isoenzyme which are distributed in the same winged bean’s mature leaves of 9 different nodes and 16 varieties by plumb plate of polyarclamide gel electrophoresis, for clarifying the rules of POD isoenzyme in the winged bean,identifying their blood relations and selecting the superior parents for cross-breeding. The results showed that the numbers of the enzyme belts in the mature leaves of 9 different nodes are 10, their Rf of which is almost identical. But the numbers are from 6 to 11 in the varieties, and the enzyme belts have obvious difference, such as the width, the color depth and so on. According to Rf of the enzyme belts and the union similarity factor (S value) of 16 winged bean varieties, we drew the following conclusions : （1）the distribution of POD isoenzyme had the high stability and the similarity in the same winged bean’s mature leaves of different nodes. （2）POD isoenzymes of the 16 winged bean varieties had obvious difference. The S values of K0006 and K0035 or zao shu 2,K0021 and K0028 were minimum, from 0.2 to 0.4,that was, the blood relations of the two groups were the estrangest from each other.They were superior parents for cross-breeding in the selected varieties. （3）we clarified the related rules of POD isoenzyme in the winged bean. The characteristics would provide us with the scientific basis of classifying the species or identifying the varieties, and have the important guiding significance to the scientific selection in the cross-breeding at the same time.