O-Carboxymethyl chitosan (CMCH) was prepared and characterized by FTIR spectroscopy. Graft copolymerization of 2-hydroxyethylmethacrylate (HEMA) onto CMCH using ceric ammonium nitrate (CAN) as an initiator was carried out in an aqueous solution. Evidence of grafting was confirmed by comparison of FTIR spectra of CMCH and the grafted copolymer as well as scanning electron micrograph (SEM) of the products. The effects of concentration of CAN, HEMA, reaction time and temperature on graft copolymerization were studied by determining the grafting percentage, grafting efficiency. With keeping other condition constant, the optimum grafting conditions was obtained as following: CMCH, 2 a; CAN, 0.2 M; and HEMA, 0.384 mol/l; reaction temperature, 40 degrees C; and reaction time, 4.5 h. (c) 2005 Elsevier Ltd. All rights reserved.