action between the appending beta-keto ester and the terminal amine is proposed. Following this method, the backbone polymer of poly[2-(acetoacetoxy) ethyl methacrylate] (PAEMA) containing the appending beta-keto ester is synthesized by reversible addition-fragmentation chain transfer polymerization and the side-chain polymer of poly(ethylene glycol) monomethyl ether containing the -NH2 terminal group (MPEG NH2) is prepared, and then the side-chain polymer is covalently bonded to the backbone polymer by the C=N bond through the coupling reaction between the appending beta-keto ester and the terminal NH2. By changing the molar ratio of the side-chain polymer and the backbone polymer, the PAEMA-g-MPEG graft polymers with G ranging from 0.07 to 0.85 are prepared. The solubility/dispersion of the graft polymers in water is studied and the G-dependent solubility/dispersion is demonstrated. The proposed method is anticipated to be a valid method to prepare graft polymers. (C) 2013 Elsevier Ltd. All rights reserved.