We　report　the　fabrication　of　long　titanium　dioxide　nanotube　arrays　with　highly　c-axis　preferentially　oriented　crystallization　and　a　high　concentration　of　oxygen　vacancies　by　second　anodization　in　ethylene　glycol　and　annealing　under　poor-oxygen　conditions.　By　optimizing　the　growth　and　annealing　conditions,　the　[001]　oriented　crystallization　is　maximized,　and　31.7%　of　the　total　Ti　ions　exists　as　Ti3+　ions.　The　carrier　density　of　the　[001]-oriented　TiO2　nanotube　arrays　is　two　orders　of　magnitude　higher　than　that　of　the　randomly　oriented　TiO2　nanotube　arrays.　The　unusual　c-textured　crystallization　confined　within　nanotubes　may　involve　the　formation　of　TiO62-　octahedra　with　a　gradient　distribution　along　the　tube　axis,　preferential　nucleation　at　the　top,　and　preferential　growth　downwards　along　the　c　axis.　Because　of　the　c-axis　preferential　orientation　and　a　high-concentration　of　oxygen　vacancies,　long　TiO2　nanotube　arrays　can　serve　as　superior　electrodes　for　both　lithium　ion　batteries　and　supercapacitors　without　the　addition　of　any　conductive　agents.　Long　c-oriented　TiO2　nanotube　arrays　deliver　reversible　capacities　of　293　mA　h　g(-1)　at　0.5　C　and　174　mA　h　g(-1)　at　5　degrees　C　with　Coulombic　efficiencies　of　over　99%,　and　hold　an　areal　capacitance　of　8.21　mF　cm(-2)　with　an　85%　capacitance　retention　after　5000　cycles.　Double　roles　played　by　oxygen　vacancies　are　identified　in　increasing　electrical　conductivity　and　activating　the　rich-Li　phase.