Shoot bark and root extracts of 16 different apple (Malus domestica Borkh.) root-stocks were analyzed for multiple electrophoretic forms of peroxidase (EC 1.11.1.7) using polyacrylamide gel electrophoresis (PAGE). Thirteen bands were seen in the peroxidase zymograms of shoot bark extracts and eight in the peroxidase zymograms of root extracts. The root peroxidase bands corresponded to ones in the shoot bark peroxidase zymograms. Two of the bands were common to all 16 rootstock patterns. The other 11 bands formed six patterns which were characterized by the presence of specific peroxidase bands. The 16 rootstocks were grouped according to banding characteristics.Key words: Apple, Malus domestica Borkh., apple rootstocks, PAGE-peroxidase zymograms