New polymer materials, based on silicone-acrylic copolymer containing cationic groups, were synthesized through radical mechanism and ring-opening polymerization of cyclosiloxane. The polymers of polyacrylate/polysiloxane improved the fastness properties of reactive dyes on cotton. In comparison with those of polyacrylate-containing cationic groups, the wash fastness and wet rubbing fastness of the dyed cotton fabric treated with the new polymer materials were better. The handle of the fabric with aftertreatment was also good. (c) 2006 Wiley Periodicals, Inc.