Piezoelectric films of ZnO and AlN have been fabricated by sputtering. The film is assessed to be of good quality by means of X-ray diffraction, scanning electron microscopy, resistivity and electromechanical measurements. The ZnO/glass and ZnO/crystal composites have been used as SAW devices. A c-axis oriented AlN film has been grown on a glass or metal film substrate at substrate temperature as low as 20∼500°C. An epitaxial ZnO and A1N film has been grown onto a basal plane sapphire substrate. A SAW propagated along c-axis of the ZnO films on the (011̄2) planes of sapphire will be available as a high frequency filter device above 1 GHz.