〔Abstract〕 Objective To study the effect of TiO2nanotubes(TNT) with differe-nt diameters on the loading of minocycline and explore its sustained release e-ffect. Methods TNT with different diameters were fabricated on the surface of titanium by anodizing at 10, 20 and 30 V, and minocycline hydrochloride(MH) was loaded on the surface to construct an antibacterial coating. The samples were characterized by electron microscopy, contact angle measurement,X-ray diffraction, Fourier transform infrared spectroscopy and UV-Visible spectrophotometer, to compare the sustained release effects. Results Anodization at 10, 20 and 30 V voltage produced 30, 70 and 120 nm nanotube coating. The 70 nm TNT had the highest drug loading and the best sustained release effect, followed by 120 nm TNT and 30 nm TNT. Conclusion The 70 nm TNT has the highest drug loading and the best sustained release effect, which is expected to improve sustained antibacterial properties of the titanium implant surface.