Abstract: Taking cherry varieties of‘Yingzhenwang’‘Mahaleb’‘Daqingye’‘Santina’‘Wanfeng’and‘Sunburst’as test materials,in house assays for resistance to stem rot were performed and the leaf thickness,epidermal cell thickness,stomatal size,activities of superoxide dismutase（SOD）,peroxidase（POD）and catalase（CAT）before and after infestation were determined to determine the cherry leaf phenotype and the role of resistance enzymes against stem rot.A preliminary determination of the resistance mechanism of cherry to anti stem rot disease by determining the leaf physiological and biochemical indexes of different resistant cherry varieties,in order to provide reference for field cultivation or breeding varieties.The results showed that the leaf thickness,the thickness of epidermal cells and the stomatal size of leaves of the six cherry varieties for testing were different.But there was no significant correlation between the difference and resistance.After cherry was infected by stem rot pathogen,the activities of SOD,POD and CAT increased,and the increasing of resistant varieties was significantly higher than that of susceptible varieties.The leaf thickness,epidermal cell thickness and stomata of cherry had no significant correlation with stem rot resistance;the resistant enzymes SOD,POD and CAT played an important role in the resistance to stem rot.