Abstract:Decapitated-derooted peanut seedlings (Arachis hypogaea L.) were smeared with 10-5 mol/L benzyladenine (BA) solution on the surface of sink leaves. 0-24h after BA treatment, the activities of sucrose phosphate synthetase (SPSase) and cytosol fructose-1, 6bisphosphatase (F1, 6Pase)were gradually increased. The decrease of acid invertase activity resulted in increasing amount of sucrose content and the increase of α-amylase activity caused the reduction of starch content. 24-48h after BA treatment, however, the activities of SPSase and F1, 6Pase decreased and acid invertase increased gradually in sink leaves. The amount of sucrose was reduced and photosynthetic carbon was favorable to the accumulation of starch.