Ion implantation technique is used for doping Co+ to single crystal TiO2(001). The implanted energies and the fluences of Co+ are 40keV and 11016cm-2; 80 keV and 51015, 11016, 51016, 11017cm-2; 120 keV and 11016cm-2, respectively. And then, the structural and the optical properties of all samples are characterized by using X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), UV - Vis diffuse reflectance spectroscopy (UV-Vis DRS), and these impurities in implanted samples are also analyzed. From the XRD spectra of implanted samples we observe that the greater damage is caused with the increase of the kinetic energy of incident ions. UV - Vis diffuse reflectance spectroscopy measurement shows that the absorbance of visible band is enhanced in all the implanted samples, and the optical band gap decreases with implanted ion fluence increasing from 51015cm-2 to 51016cm-2.