Abstract:The effect of light intensity on the stone cell in Pyrus.spp during fruit growth and development and relation of the endogenous hormone and the stone cell growing were studied. The result indicated: time of stone cell formation is from the first week to the eleventh week after flowering. The stone cell content in different light intensity is different. Its' content in thinnest light is the highest, the thin light intensity is higher, the middle light intensity is followed, and the high light intensity is the lowest. Endogenous ZR and IAA content have two peaks during fruit growth and development of Pyrus.spp. The highest content of ZR and IAA appears at the first week after blooming, and another peak of ZR and IAA appears at the seventh week after blooming. The highest content of ABA appears at the first week after blooming, and it decreases gradually. Endogenous hormone content in high light intensity is the highest, the middle light intensity is higher, the thin light intensity is followed, and the thinnest light intensity is the lowest, which showed light intensity is favor to promote endogenous hormone synthesis, to reduce the stone cell formation in Pyrus.spp.