To chemically attach beta-cyclodextrin (beta-CD) molecules to cellulose diacetate (CDA), an isocyanate containing preformed polymer was synthesized by prepolymerization of CDA and toluene-2,4-diisocyanate (TDI), which was then grafted with beta-CD. Effects of reaction temperature, time, and mixture ratio on reactions were observed. The structure of CDA-beta-CD was characterized by H-1- and C-13-NMR spectra; the release of CDA-beta-CD with medicament naproxen by dynamic dialysis in the artificial simulated intestinal fluid (pH 7.4) was Studied in vitro. Results indicated that the release time could reach more than 8 h at a graft ratio of 68.7%,, which showed a good controlled-release drug effect. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 1811-1815,2009