Abstract GaN nanowires were synthesized on sapphire substrates by chemical vapor deposition. The selective growth of GaN nanowires was obtained through an N-Ga2O3 layer prepared by radio frequency magnetron sputtering. The X-ray diffraction (XRD) and Raman measurements indicated the GaN nanowires to be all indexed to the hexagonal wurtzite structure. The photoluminescence (PL) spectra were composed of a strong UV emission peak (365nm) and a weak yellow luminescence (YL) band (~600nm). The selective growth mechanism of GaN nanowires was briefly discussed.