Cubic-based　ordered　mesoporous　TiO2　thin　films　were　prepared　by　an　evaporation-induced　self-assembly　method　through　a　carefully　controlling　the　hydrolysis/condensation　conditions.　The　obtained　sample　exhibits　mesoporous　structure　with　a　narrow　pore　size　distribution.　The　TiO2　thin　films　have　thick　inorganic　walls　composed　of　nanocrystalline.anatase.　A　reasonable　explanation　is　also　proposed　to　elucidate　the　formation　of　thick　and　stable　mesoporous　TiO2　films.　The　mesoporous　TiO2　exhibits　good　photocatalytic　activity.　Nearly　all　the　methyl　orange　has　been　degraded　by　the　mesoporous　TiO2　calcined　at　500　degrees　C.