Zinc titanate thin films of~500 nm in thickness were synthesized by an RF magnetron sputtering using a sintered ceramic target. After annealing in temperature ranges of 300-800°C, their phase transition and dielectric properties were investigated as a function of annealing temperature. Crystalline ZnTiO 3 phase was first detected at the annealing temperature of 500°C within XRD detection limit though the sputtered film was mainly amorphous. ZnTiO 3 still remained as a main phase although the slight decomposition of ZnTiO 3 into Zn 2 TiO 4 and TiO 2 occurred in association with the increase of annealing temperature. Dielectric properties were apparently improved with increase of annealing temperature and showed maximum value at 650°C. Further higher temperature annealing caused inferior dielectric property. These results were explained in terms of the presence of TiO 2 (rutile) phase, resulting from the decomposition of ZnTiO 3 phase, and the morphology of the thin film.