Abstract: Transparent and colorless nanocrystalline TiO₂ thin film photocatalysts were prepared on glass substrates by D.C. magnetron reactive sputtering method. In order to improve the photocatalytic perfor- mance, Sn ions were implanted into the surface of the TiO2 thin films using an advanced metal ion- implantation technique. X-ray diffraction （XRD） and X-ray photoelectron spectroscopy （XPS） and UV-Visible spectrophotometer were used to characterize the films. The enhanced degradation rate of Rhodamine B using TiO2 thin films implanted with Sn ions is attributed to the increased separation of electron-hole pairs in the coupled systems of the two semiconductors of TiO2 and SnO2.