Surface tensions, contact angles and conductivities of propionic acid solutions containing different amounts of chitosan were measured at a room temperature to a temperature accuracy of 0.2. The value of critical coagulation concentration (CCC) was then obtained from the plots of contact angle and conductivity versus concentration. Viscosity of the solutions with different concentrations was also measured in this work at the same temperature and from the plot of viscosity against concentration; the intrinsic viscosity was determined by extrapolation.