The (Ga(1-x)Mn(x))N nanorods were grown oil Al(2)O(3) (0001) substrates by using rf-associated molecular beam epitaxy. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected-area diffraction pattern (SADP) results showed that the (Ga(1-x)Mn(x))N nanorods had (0001) preferential orientations. XRD patterns showed that the (Ga(1-x)Mn(x))N nanorods contained a small number of grains with different preferred orientations. High-resolution TEM (HRTEM) images showed that the (Ga(1-x)Mn(x))N nanorods consisted of different preferentially oriented grains. The initial formation mechanisms for the (Ga(1-x)Mn(x))N nanorods grown on Al(2)O(3) (0001) substrates are described on the basis of the XRD, the TEM, the SADP, and the HRTEM results.