A ZnO-based fdm bulk acoustic resonator (FBAR) with a W/SiO2 multilayer reflector has been fabricated using a two-step ZnO deposition. The FEAR showed a large return loss of 35dB at similar to 2GHz and a high quality factor (high-Q) of similar to 4000. The resonance characteristics depended largely on the multilayer reflector and ZnO film.