Abstract:The peroxidase isozymes of 8 species and 2 varieties of Corydalis were analysed by means of po-lyacrylamide gel electrophoresis. According to the isoyymic zymograms, these plants may be divided into 3 groups.The taxonomy based on isozymic zymograms is in accord with that by morphology. The problem that the action of en-zymes of Corydalls species is easily weakened or lost is also discussed.