TiO2 films deposited on nano-grained titanium (NG Ti) and coarse-grained commercial pure titanium (CG Ti) by DC reactive magnetron sputtering were researched. The effects of NG Ti on the nucleation, growth, crystal structure and mechanical properties of the films were systematically studied. Scanning electron microscopy, atomic force microscope and X-ray diffraction were employed to characterize the surface morphology and crystal structure of TiO2 films. And scratch test, wear test and nanoindentation test were employed to characterize the interface bonding force, tribological properties and nanohardness of the films. The results show that NG Ti can greatly improve the nucleation rate and refine the grain size of the films, increase the nanohardness, the interface bonding force and the tribological properties of TiO2 films and promote the crystallization of rutile.