TiO2 thin films under the synthesis conditions, which could be characterized by XRD. A major peak corre- sponding to (101) reflection of the anatase phase of TiO2 was apparent at the angle of 25.40º, while the minor peaks appeared at 37.80º, 48.07º, 53.90º and 55.10º. The rutile phase could be found from un-doped TiO2 with the major peak of the (110) diffraction at the angle of 27.44º, and the minor peak appeared at 36.08º. Besides the TiO2 crystalline phases, there were two weak diffraction peaks of LaTiO3 in the 0.3 wt.% La-doped TiO2 thin film at the angle of 22.50º and 31.75º. When the content of La was 0.9 wt.%, a weak peak of La2O3 appeared at 29.30º.