This study aimed to investigate the bud dormancy mechanisms of wine grape during natural and breaking dormancy from the following physiological and biochemical aspects:water status,active oxygen and ant-oxidation system,phenols and the related enzymes.The results show that:(1)Chardonnay which is an early maturity variety comes into deep dormancy on Dec.20th,and bud dormancy starts to release gradually from Jan.29th;the late Cabernet Sauvignon’s deep dormancy stage is from Jan.9th to Feb.18th and bud dormancy starts to release gradually.Cyanamid treatment enhanced dormancy release.(2)The contents of active oxygen species O^-·₂ and H₂O₂ had a gradual increase in the early dormancy stage,reaching the peak value at the deep end-dormancy,then decreased after bud dormancy release.SOD activity decreased steadily during the whole period of end-dormancy,and then increased after the dormancy release.POD and CAT activities kept increasing during the early dormancy stage,then the POD value started to drop after the dormancy release and CAT maintained a high activity until bud sprouting.ASA-GSH cycle was relatively weak at the early stage of end-dormancy,and then it was activated gradually during the dormancy release.During the breaking dormancy,the content of active oxygen,the activities of anti-oxidation system enzymes and the contents of antioxidants are changed,all of these are better for dormancy releasing.