Synthesizing hexagonal wurtzite GaN nanowires involves nitriding Ga 2O 3 films, which deposited on GaAs(1 1 0) substrates with electrophoresis. The cylindrical structures of GaN nanowires with the diameters ranging from 40 to 200 nm and lengths up to over 100 μm have been obtained. Scanning electron microscopy (SEM) images showed the morphologies of the one-dimensional single crystal materials containing straight and curved nanowires. GaN spherical crystals attached to the fibers with diameters about 600 nm were detected for the first time. The synthesis of one-dimensional GaN nanowires can be achieved without assistance of a template of a catalyst.