Abstract: From mid-Oct to mid-Feb,2-year old potted ‘NJ72’nectarine(Prunus persica L.Batsch)was transferred at certain interxrals from field to the growth chamber at 25℃ to determine the end of bud dormancy． The results show that bud dormancy of‘NJ72’is broken by mid-Jen.The process of the onset of dormancy differs greatly among the leaf and f1ower buds．The intensity,of dormancy is lower in the flower buds compared to that in the leaf buds．In flower buds of peaches treated with low temperature，endogenous peroxide content increases soon after treatment． Catalase activity is shown to increase significantly during chilling and coincides with the increase of the activity of peroxidase and superoxide dismutasc Accumulation of peroxide is accompanied with an increase of peroxidase activity，probably due to substrate adaptability The rate of respiration of flower buds increases at low temperature during dormancy，among which the rate of the pentose phosphate pathway is also increased．while the rate of the embden-meyerhof pathway decreases and the rate of tricarboxlic acid cycle changes little Concomitantly，glucose 6-phosphate dehydrogenase activity increases at low temperature during dormanty.