Because of its wide band gap (Eg=3.37eV), low cost, and ease of manufacturing, ZnO is emerging as a potential alternative to GaN in optoelectonic applications, including light-emitting dioldes, laser diodes, and photodetectors for the UV spectral range. In the past decade, the demonstration of a large variety of functional ZnO nanowire devices has aroused growing interest in this material. Among them, ZnO nanowires show excellent UV response properties. In this paper, a prototype UV detector of MSM (metal-semiconductor- metal) structure based ZnO nanowires film was designed and fabricated, and then tested under UV illumination.