In order to expound the relationship between peroxidase isoenzyme(POD) bands,POD activity and the genealogy of mulberry varieties,the peroxidase isoenzyme of 31 mulberry varieties countrywide was studied by means of PAGE and clustered with the peroxidase isoenzyme bands.The results are as follows:(1) The result of clustering to some extent can reflect the genealogical evolve relation of mulberry varieties.(2) The relation between activity of peroxidase isoenzymes of mulberry and variety resistance is more relative.