TiO2-Al2O3 composite thin films were fabricated on soda-lime glass with sol-gel technology. By measuring the contact angle of water with the film surface and the analysis of the XRD and XPS, we studied the influence of Al2O3 doping concentration and film thickness on the hydrophilicity of the composite films. The results indicate that the doping of Al2O3 into TiO2 and the relatively large thickness of the films can improve their hydrophilicity.