Ti-6Al-4V as an implant material has bio-inert properties, so it does not support any tissues or bone cells reaction. This study aims to increase the tendency of osteoblast's cell attachment to the surface of implant Ti-6Al-4V by fabricating nanotube structure on the surface by anodization. This study also conducted to study the effect of elements from titanium alloys and organic electrolytes on the mechanism of formation of nanotube structures. The anodization method was chosen because it was easy to do, effective, and inexpensive. The samples were prepared by ground and polished, then washed by ultrasonic. Anodization used organic electrolytes in the form of a mixture of ethylene glycol, 0.5 M NH4F, and 4 w.t% deionized water. The study of the effect of voltage and duration time was carried out to understand the mechanism of nanotube formation, through morphological observation on the surface and cross-section area of nanotubes using SEM and characterization of elements using EDS, diameter, and length of highly ordered nanotubes was observed. The results of the characterization showed that the tube diameter is adjusted by the voltage, while duration time influence the tube length, with a linear relationship, so the widest diameter achieved at 40V 5h, but the longest tube achieved at 30 V 5h. Whereas for 5h duration, the upper part of the tube collapsed and disintegrated. The fluoride ions incorporated at the tube surfaces formed fluoride-titanium oxide cubic agglomerates, and the whole nanotube surface was oxide.