To elucidate the relationship between reflorescence and nutrition conditions,were investigated the organic nutrition changes in shoots and flower buds from the Pyrus pyrifolia cv.Hosui during reflorescence.The results showed that:(1)along with the bud break at 6 d defoliated by hand，the budding rate was keeping low rising,and flowers opened fully at 42 d.(2)The soluble sugar was increased firstly when the tree defoliated by hand.However,the soluble sugar content was decreased at the 12 d of rapid increasing stage for budding rate.The budding rate increasing stage was consistent with starch contents reducing periods in shoots.In addition,protein content in shoots was decreased to promote rapid increasing for the free amino acid content in the flower buds.(3)The related positive or negative correlation for budding rate and starch content,soluble protein content in flower bud and shoot reached at the 1% significant level,respectively.The positive correlation for budding rate and soluble sugar content in flower bud were 0.794,reached at the 5% significant level.It was indicated the nutrition conditions played important roles in the reflorescence occurrence for Pyrus pyrifolia cv.Hosui.