By　a　combination　of　cold　plasma　treatment　and　sol-gel　dip-coating　technology,　defective　TiO2　bilayer　films　were　successfully　prepared,　and　then　the　defect　was　characterized　by　X-ray　photoelectron　spectroscopy　and　electron　spin　resonance.　The　photocatalytic　activity　and　photoinduced　superhydrophilicity　of　the　films　were　evaluated　by　the　photocatalytic　degradation　of　organic　dyes　and　water　contact　angle　measurement　in　air,　respectively.　Compared　to　the　conventional　TiO2　film,　the　TiO　2　bilayer　films　with　defects　provide　much　higher　efficiency　in　photocatalysis　and　photoinduced　hydrophilicity.　Moreover,　it　is　found　that　the　introduction　of　defect　sites　at　the　interface　of　two　TiO2　layers　results　in　a　significant　improvement　in　the　photonic　efficiency　due　to　the　generation　of　electron　trapping　states.　The　defect　sites　can　inhibit　the　recombination　of　electron-hole　pairs　and　thereby　increase　the　concentration　of　photogenerated　carriers　at　the　film　surface,　leading　to　an　enhancement　of　quantum　efficiency　of　TiO2　films　under　UV　irradiation.　Furthermore,　the　defects　located　at　the　interface　between　two　TiO2　layers　show　higher　stability　as　compared　with　that　located　at　the　outermost　surface　of　TiO2　films.　In　addition,　the　fabrication　of　the　interface　defective　TiO2　multilayer　film　is　convenient　and　of　low　cost.　The　study　demonstrates　that　this　modified　strategy　is　practical　for　promoting　the　photoinduced　properties　of　TiO2　multilayer　films.　©　2012　American　Chemical　Society.