Wurtzite GaN nanorods have been successfully synthesized on Si(111) substrates through ammoniating Ga 2 O 3 /Nb films under flowing ammonia atmosphere at 950 ∘ C in a quartz tube. The nanorods have been confirmed as hexagonal wurtzite GaN by X-ray diffraction (XRD) and selected-area electron diffraction (SAED). Scanning electron microscopy (SEM) and field-emission transmission electron microscope (FETEM) reveal that the nanorods are straight and uniform, with a diameter of ranging from 100 to 200 nm and lengths up to several microns. The photoluminescence spectra (PL) measured at room temperature only exhibit a strong emission peak at 368.5 nm. Finally, the growth mechanism of GaN nanorods is also briefly discussed.