Graphene on gallium nitride (GaN) will be quite useful when the graphene are used as transparent electrodes to improve the performance of gallium nitride devices.In this work, we report the direct synthesis of graphene on GaN by a self-catalyzing technique.Graphene can be directly grown on GaN at 950℃ and under atmospheric pressure without catalysts, which is confirmed by distinct G peak and 2D peak.Meanwhile, the effects of the surface morphologies of GaN (GaN with smooth surface and with rough surface) on the growth of graphene were also studied.