One-dimensional gallium nitride (GaN) nanostructures have both GaN mat erial advantages and low-dimensional features,which can be used to study the electrical mate rials,thermal conductivity,mechanical properties and di mensions,due to their unique applications in mesoscopic physics and nano-devices.In order to obtain pure ni tride nanowires,this paper researches a way on the growth of GaN nanowire array without any metal catalyzer .With the aid of hydrochloric (HCl) gas,an array of GaN nanowires without any me tal impurity was grown on a 3μm GaN/sapphire template in a hydride vapor phase epitaxy (HVPE) reaction chamber.Variable structures of the GaN nanowires corresponding to different temperatures (700℃,780℃ and 900℃) were characte rized by scan electron microscopy (SEM) image,transmission electron microscopy ( TEM) image and energy dispersive X-ray spectroscopy (EDX),which indicate that the growth of GaN nanowires is obviously sensitive to temperature.A uniform vertical array could be got at 780℃,and the diameter and length of the corresponding GaN nanowire are about 80nm and 1.5μm,respe ctively.Moreover,the growth mechanism of the GaN nanowires is explored,which suggests that the hyd rochloric gas plays an important role as catalyer during growth process.