Abstract: In order to study the dwarfing mechanism of Yu dwarf rootstock No.1， the leaves from Yu dwarf rootstock No.1 and Kansu peach at different growth stages in June， August and September were selected as materials， their differentially expressed proteins were analyzed by two\|dimensional gel electrophoresis. The results of 2\|DE maps showed that peach proteins could be effectively extracted by the lysis buffer containing thiourea with less background， clear protein pots and good repeatability when 90 μg protein was uploaded. The 2\|DE maps of Yu dwarf rootstock No.1 in June， August and September isolated 557， 554 and 441 protein spots， respectively， while 548， 529 and 427 protein spots were detected in Kansu peach at the same stages. Sixteen differentially expressed protein spots between Yu dwarf rootstock No.1 and Kansu peach were selected. Twelve proteins were specifically expressed in June and three proteins were specifically expressed in August in Yu dwarf rootstock No.1， while one protein were differentially expressed in both August and September between Yu dwarf rootstock No.1 and Kansu peach.

Key words: peach, Yu dwarf rootstock No.1, two\, dimensional gel electrophoresis, dwarfing mechanism