ZnO nanowire thin film was prepared by chemical solution method and a ZnO nanowire-based electroluminescence device has been successfully developed. The device was driven by the alternating current and presented a good RC behavior. Under the action of applied bias, light emission in the ultraviolet region with the wavelength of 387 nm and in the visible region with 552 nm has been observed. The mechanism of electroluminescence and its frequency dependence are discussed in this paper by analyzing the electric properties of the device and the structure of energy band of ZnO semiconductor.