Abstract: To understand the physiology of pruning responses，we studied the effects of various pruning methods（cutting back，branch-bending，bud-notching and girdling）on the endogenous hormones of young Fuji apple（Malus × domestica Borkh.）buds. Results showed that endogenous hormones in buds at the different positions of the branches were significantly different. Buds at the basal parts of the branch contained higher IAA and ABA content，and cytokinins and gibberellin content in the buds at the distal parts of the branch was significantly higher than basal parts. Compared with control group，cutting back treatment decreased IAA and ABA content in the buds at the middle and proximal parts of the branch. Contrary to cutting back，branch-bending increased IAA and ABA content. In addition，cutting back treatment increased GA₃，ZR contents in the buds at the middle and basal parts of the branch，but fail to change the intrinsic distribution gradient of hormone in the different parts of the branch. Branch-bending，on the other hand，totally changed the intrinsic distribution gradient of hormone in the different parts of the branch. Bud-cutting treatment broke the original balance between endogenous hormones in the buds，growth promoting hormones such as IAA，GA₃，ZR increased significantly，and the growth inhibiting hormone ABA levels decreased.

Key words: apple, cutting back, branch-bending, bud-notching, endogenous hormones, pruning