Li 1 . 1 8 Nb 0 . 8 2 Ti 0 . 1 8 O 3 thin film, which has LiNbO 3 -based subcell and resultant superstructure along its c-axis, was prepared on Al 2 O 3 (0001) single-crystal substrate from alkoxide solutions by a sol-gel and a spin-coating process. The high-temperature X-ray diffraction measurement indicated that the coated gel film was crystallized at 500 o C, and the superstructure was formed at 800 o C. Thickness of the prepared film was typically 100 nm, and was synthesized by a one-step coating process. In order to achieve coexistence of preferred orientation with superstructure in a thin film, a two-step heat treatment was found to be an appropriate method. The layer of the superstructure was parallel to Al 2 O 3 (0001) substrate. Some distribution of layer distance was observed by XRD and TEM. However, the degree of preferred orientation for two-step heat-treated film was estimated to be 1.0 by XRD, showing the advantage of the present processing to fabricate preferred-oriented superstructure thin film.