Some dilute solution properties of chitosan with different degree of deacetylat-ion (D.D) have been studied by viscometry and light scattering in the 0.1mol/l CH3COONa/0.2mol/l CH3COOH buffer solvention. The results indicated that the va-luesf or constant k and a in the Mark-Houwink equation were regularly dependent on D.D And it was found that the higher the D.D was

the larger the molecular size z2/1

intrinsic viscosity [η] and the expansion factor aη became

under the same molecular weight because of the polycation behavious of chitosan.But the co-nformation parameter and characterstic ratio Coo diminished with increasing of D.D.