High purity chitosan, a natural biodegradable polymer, was used as a staling material for obtaining three di9:rent molecular weight chitosans(830, 46, 8 cP). From these three different chitosans, solutions were prepared using acetic acid as a solvent, changing treatment concentration(0.05%~ 1.0%). Conon woven fabric samples were dipped, pre-dried, neutralized, and heat-set. The mechanical, physical properties of the chitosan treated fabrics, including tensile, shear, bending compression, surface friction, air permeability, and white index, were determined. The increase in the chitosan viscosity and chitosan concentration lowered WT(tensile energy) reading of the treated fabrics, and increased shear rigidity, bending rigidity, bending hysteresis. Yellowing of the treated fabrics was not noticeable, since the purity of the chitosan was high enough.