The possibility of separation of ethanol-water mixtures was investigated by pervaporation through PVA（poly vinyl alcohol） membranes. PVA membranes allowed preferential pervaporation of water over ethanol, and showed the selectivity of about 2-20 for the mixtures with high ethanol content above 0.7 mole fraction. But, they are nearly effective for dehydration of the mixtures with low ethanol content. The permeate flux were about 0-2.0 liter/hr·㎡ for high-content ethanol mixtures. Both selectivity and permeate flux could be increased by increasing the operating temperature and decreasing the pressure in permeate side.