The seedling male sterile plants ‘Y-14’ and ‘Sunshine Muscat’ were used as test materials to study the changes of antioxidant enzyme activity and endogenous hormone contents during the bud development period, for demonstrating the physiological and biochemical characteristics of male sterility in grapes. The results showed that: (1) compared with ‘Sunshine Muscat’, the activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in the buds of ‘Y-14’ were significantly reduced, while the content of malondialdehyde (MDA) increased significantly. (2) The content of auxin (IAA) in ‘Y-14’ was higher than that in ‘Sunshine Muscat’, and the content of abscisic acid (ABA) was significantly lower than ‘Sunshine Muscat’; In the early stage of bud development, the content of gibberellin (GA₃) in ‘Y-14’ is lower than ‘Sunshine Muscat’, while methyl jasmonate (MeJA) is significantly lower than ‘Sunshine Muscat’ in the later stage; the content in ‘Y-14’ trans-Zeatin Nucleoside (TZR) is lower than that in ‘Sunshine Muscat’. (3) In the early mononuclear stage, the content of ABA in ‘Y-14’ changed smoothly while the ‘Sunshine Muscat’ increased sharply. At the same time, the content of GA₃ began to be higher than that in ‘Sunshine Muscat’, while the MeJA began to be lower than ‘Sunshine Muscat’ in the early mononuclear stage. And it showed gradually significant difference. In summary, the abnormal changes of SOD, POD, CAT activities and MDA, IAA, ABA, GA₃, MeJA contents may have led to the male sterility. The early mononucleus period may be the critical period for the male sterility of ‘Y-14’.