Abstract: Peroxidase isoenzymes of leaves in Ziz ip hus spinosus Hu. and 17 varieties of Z. jujuba Mill. were analyzed by means of perpendicular􀀁plate type of polyacrylamide gel electrophoresis. Fuzzy cluster analysis was conduc􀀁
ted based on the similarity coefficients of the isoenzyme zymogram, using the R􀀁chain link method of similarity relation ship. Z . spinosus Hu. and 17 varieties of Z. jujuba Mill. were classified into several groups. and the relationship among the groups was discussed. From the phenotype of molecular enzyme level, it has been proved that Z. spinosus is the primeval species of the cultivated Z. jujuba, which is the result of a longtime evolution. But both species are closely related to each other.

Key words: Ziziphus jujuba Mill., Ziz ip hus spinosus Hu., Peroxidase isoenzymes, Primeval species, Phylogenetic relationship