The present study investigates the pervaporation performance of crosslinked chitosan membrane for the dehydration of aqueous pyridine solution. The control of the degree of crosslinking contributes to an improved pervaporation performance of chitosan membranes. The chitosan membrane crosslinked with 4.515 x 10(-4) (mol/g polymer) glutaraldehyde solution shows the separation factor of 510 and the flux of 140g/m2hr measured with 93wt% aqueous pyridine solution at 25-degrees-C.