The　introduction　of　oxygen　vacancies　(V-o)　in　various　oxide　nanostructures　has　been　extensively　used　to　modify　their　physical　and　chemical　properties.　Here,　we　report　on　a　N-2-flow-annealing　method　for　introduction　of　V-o　in　titania　(TiO2)　nanotube　arrays　prepared　by　potentiostatic　anodization　of　Ti　plates.　The　investigation　of　their　V-o-related　optical　and　ferromagnetic　properties　shows　that　the　arrays　annealed　in　a　strong　N-2　flow　exhibit　stronger　visible-NIR　absorption　and　room-temperature　ferromagnetism　than　the　ones　annealed　in　sealed　N-2.　The　two　enhanced　properties　may　stem　from　the　introduction　of　a　high　concentration　of　V-o,　whose　formation　is　facilitated　by　a　strong　N-2　flow　field　over　the　nanotube　arrays.　(C)　2011　Elsevier　B.V.　All　rights　reserved.