A modified one-bilayer polyelectrolyte reverse osmosis membrane was fabricated using poly(allylamine hydrochloride) and poly(sodium-4-styrene sulfonate) as polycation and polyanion, glutaraldehyde as a crosslinker and polyethylene glycol (PEG-600) as a surface modifier by the spraying assisted layer-by-layer assembly method. The results show that the PEG modified membrane possesses higher permeate flux (ca. 21 L/m(2)h) than the unmodified one (ca. 3 L/m(2)h) with a similar salt rejection. Furthermore, the PEG modifier dramatically enhances the membrane anti-microbial property (ca. 98.6%).