LiNb 1 - x Ta x O 3 films were prepared by a thermal plasma spray CVD method using liquid source materials. Preferentially (001)-oriented LiNb 1 - x Ta x O 3 films with satisfactory in-plane and out-of-plane alignment were fabricated on sapphire (001) substrates. The full-width at half-maximum (FWHM) of the (006) rocking curve could achieve 0.12 o , which was comparable with those of LiNbO 3 and LiTaO 3 films prepared by other conventional vapor-phase deposition methods. The deposition rate was up to 0.07μm/min, which was 5-40 times faster than those for most other conventional vapor-phase deposition methods. From inductively coupled plasma atomic emission spectroscopy analysis, x values of these films were estimated to be 0.36-0.49.