A new type of amphiphilic derivative of carboxymethylchitosan(CMCHS) was prepared by reaction of CMCHS with p-nonylphenyl glycidyl ether. The structure of the resulting derivatives, i.e., (2-hydroxyl-3-p-nonylphenoxy) propyl-carboxy-methylchitosan(HNP-CMCHS) had been identified by UV and IR spectroscopy. They are water-soluble and have surface activity, which is related to the degree of substitution and the added electrolyte in the solution. In the presence of NaCl, two transitions appeared on the surface tension-concentration plots, that means the possibility of the formation of intramolecular micelle. It was also found that it need a long time for the surface tension of the derivative solutions to get a equilibrium value and the time is related to the derivative concentration, degree of substitution and added electrolyte of the solution.
