The viscosities of chitosan-HAC in aqueous solution with various amount of NaAC have beenmeasured.Based on the analysis of experimental data,an empirical equation is deduced to des-cribe the relationship between the intrinsic viscosity and the concentration of external salt in thechitosan solution:[η]=[η];+P/m;and another empirical equation is proposed for describing the variation of reduced viscosity ofchitosan solution as function of salt and chitosan concentrations:(η;/c);={D+A/（1+BC+HC;）}·{1-1/(（[η];=0）/([η];-[η];)+P/m;)+（C;m;}where the first term represents the relationship between viscosity and polymer concentration in theabsence of external salt,while the second term represents the correction value on viscosity in thepresence of external salt.
