The changes in peroxidase activity and peroxidase isozyme pattern were examined with different parts of legume(soybean, red-bean and mung-bean) seedling. The activity of peroxidase showed a tendency to increase at an early stage, and then decrease gradually as germination continued. The activity of catalase and the contents of hydrogen peroxide from red-bean seedling decreased in cotyledon, root and epicotyl fraction throughout germination, while those of shoot fraction increased. IC was found that the activity of catalase is related with contents of hydrogen peroxide. Also, the changes in peroxidase isozyme pattern in root fraction were remarkable as compared with those in other fraction. As the time elapsed after germination the number of isozyme bands increased, being 5, 6 and i in soybean, red-bean and mung-bean, respectively. These results suggest that the peroxidase isozymes may be directly correlated with the differentiation and leguminous plants.