The chitosan samples with various degree of deacetylation were prepared by the reaction of N-acetylation between chitosan and acetic anhydride. The samples were characterized by FTIR and ultraviolet spectrum. The mechanical and fat resistance properties of hand-sheet coated by chitosan with different D. D. value were measured. The results indicated that there is a line correlation between D. D. value and the amount of the added acetic anhydride, while the molar ratio of acetic anhydride and chitosan is below 0. 6; the mechanical and fat resistance properties are improved as the weight of coating arises; the resistance index is improved by 50. 3% when the weight of coating reaches 4. 8 g / m2 ; at the same amount of coating weight, the resistance index decreases gradually as the D. D. value of chitosan decreases; while the weight of coating is above 2. 32 g / m2 , the increasing of fat resistance index slows down; the mechanical and fat resistance properties are greatly influenced by the microstructure of the film formed by chitosan.