The graft copolymerization of acrylamide onto cellulose by Ag+-S2O8-- redox initiation system was studied. It was found that the redox system consisted of Ag+-S2O8-- easily initiates for the grafting of acrylamide onto cellulose in aqueous system at room temperature. The graft reaction was proportional to the concentration of [Ag+].[S2O8--] when [Ag+] or [S2O8--] was low. In the initial stage of reaction, the value of activation energy obtained by Arrhenius plot was about 8.66 Kcal/mol.