Abstract: To discuss the relationship between mineral nutrient and pear fruit calyx persistency or shedding，the pear cultivar‘Dangshan Suli’was used as experiment materials，and the mineral elements contents in fruitlet and its calyx were tested during 5 d to 25 d after full bloom，the demand on different mineral elements for the young fruit and sepals growth were studied. The effect of Fe to fruit sepal’s growth was discussed by spraying of GA3，PP333 and FeSO4 at the full bloom stage. The correlation analysis was carried out in mineral and chlorophyll contents in fruitlet sepals. The results showed that the Fe content difference between in fruitlet and in its calyx whose Fe content was 6.13 times higher than that in fruitlet was the biggest among the tested nine mineral elements. During the sepal developing process，the iron demands were obviously higher than the fruitlets but at the same time of less demands for other mineral elements. The percentage of calyx persistency fruit，Fe content in fruitlet and its calyx were all increased under the spraying of 400 mg · L-1 GA3. On the contrary，the percentage of calyx persistency fruit and the Fe content were decreased under the treatment of 2 500 mg · L-1 PP333，otherwisely，the calyx persistency fruit percentage was increased after spraying 0.3% FeSO4 solution too. So it was postulated that the sufficient Fe content was the guarantees to both fruit calyx development and the fruit calyx persistency. There was a positive correlation between Fe and Chl.a content dynamic changes in fruitlet calyx，it indicated that the abundant of Fe was probably used for Chl.a synthesis.　　

Key words: pear, calyx, development, Fe