A beta-cyclodextrin derivative grafted chitosan (CDD-C) was synthesized with chitosan and carboxymethyl-beta-cyclodextrin (beta-CD). Its structure was characterized by elemental, infrared spectra, and X-ray diffraction analyses. The degree of substitution by the carboxymethyl beta-CD moiety achieved 0.27 with the addition of DMF to the reaction solution. The results are in agreement with the expectations. The static adsorption properties for guanosine, cytidine, and uridine were studied. Experimental results demonstrated that CDD-C had higher adsorption capability for guanosine than cytidine and uridine, and the adsorption capacity for guanosine was 74.20 mg/g. The adsorption capacity was greatly influenced by pH, time, and temperature. The introduction of chitosan enhanced the adsorption ability and adsorption selectivity of beta-CD for guanosine. This novel derivative of chitosan is expected to have wide applications in separation, concentration, and analysis of guanosine, cytidine, and uridine in biological sample. (c) 2006 Wiley Periodicals, Inc.