Abstract: To make clear the physiological responses of apple trees grafted on three rootstocks under high level of manganese stress. The physiological responses and manganese accumulation of three rootstocks on 400 mg · kg^-1 manganese stress were studied. The results showed that toxic symptom happened in new leaves of all apple trees grafted on three rootstocks，which was the most serious in Malus baccata（Linn.）Borkh.，followed by Liaozhen 2 inter stock，the most lightly in Malus prunifolia（Willd.）Borkh. Under 400 mg · kg^-1 Mn stress，the growth of apple trees on Malus baccata（Linn.）Borkh. and Liaozhen 2 inter stock were restrained significantly，but the growth of apple trees and Mn accumulation in underground parts on Malus prunifolia（Willd.）Borkh. were promoted，the contents of ROS and MDA were declined sharply，the SOD activity and AsA content increased slightly in apple leaves on Malus baccata（Linn.）Borkh. and Liaozhen 2 inter stock. There were no significant difference of ROS content and a little rise of MDA content because of the much larger increases of antioxidant enzymes of SOD，POD，CAT and antioxidants such as AsA under the high level of Mn stress. The rootstocks of Malus prunifolia（Willd.）Borkh. had higher endurance to manganese toxcity，and Malus baccata（Linn.）Borkh. and Liaozhen 2 inter stock were relatively lower.

Key words: apple, rootstocks, manganese, stress, biomass, accumulation, antioxidant system