In this paper, we deposited high quality ZnO film by plasma-assisted Metal-organic Chemical Vapor Deposition (MOCVD). A dominant peak at 34.6 degree due to (002) ZnO was observed indicating strongly C-oriented. The full-width at half-maximum (FWHM) of the (-rocking curve was 0.56 degree showing relatively small mosaicity. Transmission spectrum showed that the bandgap of ZnO film was about 3.31 eV at room temperature. Photoluminescence (PL) measurement was performed at both room temperature. Ultraviolet (UV) emission at 3.30 eV was found with high intensity at room temperature while the deep level transition was weakly observed at 2.513 eV. The ratio of the intensity of UV emission to that of deep level emission was as high as 193, which implied high quality of ZnO film. The resistivity of ZnO film was increased after annealing under Oxygen while its optical quality decreased.