N-carboxymethyl chitosans (N-CMC) were synthesized from chitosan in water with chloroacetic acid instead of comparatively expensive glyoxylic acid. The optimal reaction conditions were 90 degrees C and 4 h with a ratio of chloroacetic acid to chitosan 5 : 1(w/w). The degree of substitution of product exceeded 1.32. The N-carboxymethyl chitosans were characterized by XRD, FTIR, H-1-NMR, and the water solubility and isoelectric point of N-CMC with different degrees of substitution were determined. FTIR and H-1-NMR data has confirmed that the substitution reaction occurred on the amino groups. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 119: 3282-3285, 2011