Nano-structured titanium coating was obtained by alkali treating the vacuum plasma sprayed samples following hot water immersing for 24 h. The influences of the surface microstructure on the biological performance were studied. A canine model was applied for in vivo evaluation of the bone bonding ability of the coatings. The histological examination results demonstrate that new bone was formed more rapidly on the nano-structured coating implants and grew into the porosity than the as-sprayed one. After 4 weeks implantation, the nano-structured implants were found to appose directly to the surrounding bone while large lacunae could still be observed at the interface between the as-sprayed samples and bone. All these results indicate that a nano-structured surface on the porous titanium coating is favorable for bone bonding.