TiO2 thin films were prepared on microscope glass slides by radiofrequency magnetron sputtering method under different flow ratios of Ar and O2 gases. The films were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), Raman spectroscopy and UV-VIS spectrophotometer. The results indicated that the film prepared under the flow ratio of ArO2=20 sccm5 sccm has a higher photocatalytic activity.