Abstract:ZnO thin film is a compound semiconductive material of hexagonal Wurtzite structure with a wide application in many areas such as transitive conductive window materials, ultraviolet detectors, LEDs and LDs luminance devices due to its unique electrical and optical properties, good chemical stability, high active energy and melting point, abundance, cheap and nontoxic source, and relatively low preparation temperature. Recent researches show that the properties of ZnO thin film are greatly changed while being doped with some elements. In our experiment, high quality ZnO thin films doped with CeO2 were prepared by RF magnetron sputtering technique. The influence of CeO2 on the structure and optic absorption property was studied by XRD apparatus and UV-visible spectrophotometer. The results show that the CeO2- doped films have a prominent effect on the developing ways of crystal grains and UV absorption property. The lattice relaxation and the content of second phase increase when more Ce is doped. ZnO crysal grains grow in mixing directions. The element Ce exists in many forms in the film. The film's UVA absorption is enhanced. The ultraviolet absorption peak becomes wider and the absorption intensity increases. The slope of the absorption margin is increased and the absorption edge obviously moves to short wave direction when more Ce is doped. In addition, the breadth of the absorption peak is increased and the absorption intensity improved. The visible absorption increases in some extent.