An ionically surface crosslinked chitosan composite membrane was prepared for pervaporation of ethylene glycol-water mixture. Chitosan membranes exhibited an optimum dehydration performance from ethylene glycol (EG)-water mixtures at 80 min crosslinking time. At 80 degrees C and 80wt% feed EG concentration, permeation flux of 1130 g/m(2)h and water concentration of permeate greater than 99.5 wt% were achieved. Effects of operational conditions including feed EG concentration, operating temperature, and annealing temperature of chitosan membranes on the pervaporation performances of chitosan composite membranes were investigated. At EG concentrations from 70 to 95 wt%, water concentration was higher than EG concentration in the permeate and permeation flux decreased with increasing feed EG concentrations. Annealing of chitosan composite membranes reduced the permeation flux and separation performance of chitosan composite membranes. At high EG concentration in the feed mixture, the membrane was more sensitive to operating temperatures and had higher activation energy of permeation. Water selective chitosan membranes can be applied to evaporation-pervaporation hybrid system for dehydration in the recycle of anti-freezing agent and EG production process.