Chitosan (CS) is a biocompatible, biodegradable, and nontoxic polysaccharide polymer. It dissolves in water only if the pH is lower than 6.5. To extend its range of application, many water-soluble derivatives have, therefore, been prepared. In this research, chitosan-vitamin C complexes (CSVC) were synthesized and characterized with FTIR, DSC, and H-1-NMR. The solubility of CSVC in distilled water was greatly improved. The center dot O-2(-) scavenging activity of CSVC was compared with CS and vitamin C (VC) by measuring the auto-oxidation rate of pyrogallic acid. Results showed that the scavenging activity on center dot O-2(-) by CSVC was stronger than that by CS. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 114: 2986-2991, 2009