The chilling requirement and heat requirement of 10 peach cultivars were investigated.And the relationship between chilling requirement and heat requirement,as well as the effect of different chilling accumulation on heat requirement were also systematically studied.There were no regular relations observed between vegetative buds and floral buds on the amount of chilling requirement or heat requirement.However,the distribution of chilling requirement and heat requirement followed certain rules respectively in vegetative buds and floral buds.Leaf buds with a lower chilling requirement usually had a lower heat requirement while flower buds with a lower chilling requirement usually had a higher heat requirement.Heat requirement was affected by the duration of chilling exposure.Regarding the deficient chilling exposure,although budburst exited,the budburst rate was far less than the requirement of production,and the heat requirement tended to infinity.In the matter of sufficient chilling exposure,heat requirement declined as chilling exposure increased.This research also revealed that there was a suitable quantity of chilling exposure which minimized the total time of chilling and heat exposure.