After investigation and analysis in orchard,the peak of calyx dropping was found on 8 th day after full bloom.Whether calyx of the most young fruit was dropped or not often appeared at 8 days after full bloom.The ability of calyx dropping became stronger with its order place rising in the same inflorescence.Fruit end sticked up at end of June.The reason why calyx fruit end sticked up is that there was a longer calyx sepal canister on the top of fruit,when calyx dropped.Artificial cutting calyx can make most presistent calyx fruit be low-lying end one.Calyx dropping is positively correlative with the hollow of fruit top,and persistent calyx fruit had positive correlation with bulge of fruit too,and the two of correlation coefficients were 0.994 and 0.957 respectively.