Zeolite-filled polydimethylsiloxane/polysulfone composite membranes were prepared and used to separate ethanol from dilute ethanol-water mixtures through a pervaporation process. During this process the relationship between flux (J) and temperature (T)is J = 597.95 exp(-E(0)/RT) (g/m(2) . h), E(0)=3.292 kJ/mol. The experimental results show that the flux decreases with increasing downstream pressure while the selectivity (alpha(EtOh/Water)) rises, the flux increases, and the selectivity decreases with a rise of feed concentration, and the flux as well as the selectivity increase with increasing bulk velocity on the upstream side of the membrane.