TiO2/4A zeolite composite catalysts were prepared by coating TiO2 on 4A zeolite via liquid phase deposition. The TiO2/4A zeolite composite catalysts wtih higher surface weak acidity and lower mediate strong acidity exhibit much better catalytic performance on ethanol dehydration to ethylene compared with 4A zeolite. It is suggested that the TiO2 promoter could improve the effective Lewis acidity of composite catalyst which consequently enhanced the catalytic performance.