Highly ordered nanotube arrays were fabricated via electrochemical anodization of Ti-6Al-4V (TC4) alloy foils in aqueous fluorine containing electrolytes. The formation of ordered nanotubular films was affected by the applied anodization potential and the anodization time. The optimal applied voltage and anodization time were 20V and 1h, respectively, as-prepared anodic nanotubular films were in highly ordered with the average inner diameter of about 120nm, the wall thickness of 17nm and the tube length about 300nm. The tubular nanostructures were examined by field emission scanning electron microscopy. The possible nanotube formation mechanism was also discussed.