Supported　multicomponent　membranes　with　photocatalytic　antifogging　property　were　prepared　by　the　improved　sol-gel　method,　The　influences　of　preparation　and　experiment　conditions　such　as　thickness　of　membrane,　temperature　and　time　of　sintering,　light　source,　and　intensity　of　illumination　on　hydrophilicity　of　the　membranes　were　studied　by　using　XRD,　AES　and　water-contact　angle　measurement,　The　results　show　that　TiO2　crystal　type　and　specific　surface　area　of　the　membrane　are　the　important　factors　affecting　the　hydrophilicity　of　the　photocatalytic　antifogging　membrane,　The　water-contact　angle　is　decreased　with　increasing　the　specific　surface　area　and　the　content　of　anatase.　Hydrophilicity　of　the　membrane　was　also　determined　by　thickness　of　membrane　due　to　the　amount　of　catalyst　and　efficiency　of　UV　light　absorption,　It　was　found　that　the　hydrophilicity　has　a　step-response　to　intensity　of　illumination,　Sunlight　illumination　has　a　similar　efficiency　to　the　ultraviolet　lamp　for　recovering　and　maintaining　hydrophilicity　of　membrane.