Abstract: Oriented GaN nanowires（NWs） were prepared by using metalorganic chemical vapor depositionon（MOCVD）.The GaN（0001） coated sapphire is used as substrate with Ni/Au catalyst on it,Trimethylgallium（TMGa） and NH₃ were used as sources,the nanowires were grown under high temperature.Experiment result shows that the morphology of the nanowires under the influence of growth temperature,good morphology nanowires can be grown at 750℃.The thickness of the catalyst affects the nanowire’s growth mechanism and the orientation.Oriented GaN nanowires can be prepared by Two-step growth method.