This study was carried out during 2006 and 2007 seasons to study the effect of some dormancy - breaking chemicals on bud burst, vegetative and floral bud percentage and histological structure of buds of "Le Conte" pear trees. The data revealed that, spraying Le-Conte pear trees at 1^st February with Dormex at 2% alone or at 1% combined with mineral oil at 3% as well as commercial fertilizer NPK at (4-5-40) 4% were more effective in bud burst as well as early of floral initiation and flower opining compared with control one, but Dormex application at 1% plus mineral oil at 3% was the best in this respect.