A flocculant based on chitosan was prepared, and its flocculation behavior was studied. The graft copolymer of acrylamide onto chitosan was synthesized using potassium persulfate as an initiator. The effect of reaction conditions, i.e., deacetylation degree of chitosan (CTS), the effect of the concentration, solution pH, and the initial concentration of kaolin on flocculation characteristics of chitosan-grafted polyacrylamide (CAM), was discussed. The experimental results showed that the higher the deacetylation degree of chitosan, the better the flocculation performance of CAM. The concentration and pH of flocculant solution had a great impact on the flocculation performance. Compared with chitosan, the graft copolymer had a better flocculating effect on the kaolin suspensions. (C) 2011 Wiley Periodicals, Inc. Adv Polym Techn 31: 292297, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.20252