The　thin　films　of　order-aligned　titania　nanotubes　were　fabricated　by　anodic　oxidation　method　in　the　electrolyte　of　0.5　mol/L　NH4HF2+1　mol/L　NH4H2PO4　aqueous　solution　and　characterized　by　X-ray　Diffraction　(XRD),　Scanning　Electronic　Microscopy　(SEM),　and　Transmission　Electronic　Microscopy　(TEM).　The　experiment　results　show　that　the　applied　voltage　has　a　great　effect　on　the　microstructures　of　the　thin　films　of　titania　nanotubes.　The　order-aligned　titania　nanotubes　of　1.8　mu　m　in　length,　of　100　nm　in　outer　diameter　and　80　nm　in　inner　diameter　have　been　prepared　at　the　voltage　of　20　V　for　8h　in　the　electrolyte　of　0.5　mol/L　NH4HF2+1　mol/L　NH4H2PO4　aqueous　solution.　The　titania　crystals　in　anatase　type　were　obtained　after　annealed　at　300　degrees　C　for　2　h　with　the　heating　rate　of　10　degrees　C/min.　The　growth　mechanism　of　titania　nanotubes　was　proposed　via　the　study　on　the　fabrication　processing　in　this　paper.