The reverse osmosis process needs no phase transformation during separation, and thus it has a potential in saving energy for liquid mixture separations. Application of reverse osmosis to organic liquid is limited, owing to the lower stability of polymer membranes against organic liquid. Zeolites are inorganic materials having durability against organic liquid and heat, and they show good separation ability in pervaporation. In this study, zeolite membrane was firstly applied to the reverse osmosis process. Zeolite A membrane, having thickness around 5 mu m, showed 0.44 rejection from 10wt% ethanol water mixture. The membrane was stable to applied pressures up to 50 kgf cm(-2).