The present invention relates to a GaN transistor, and a method of fabricating the same, in which a structure of a bonding pad is improved by forming an ohmic metal layer at edges of the bonding pad of a source, a drain, and a gate so as to be appropriate to wire-bonding or a back-side via-hole forming process. Accordingly, adhesive force between a metal layer of the bonding pad and a GaN substrate is enhanced by forming the ohmic metal at the edges of the bonding pad during manufacturing of the GaN transistor, thereby minimizing a separation phenomenon of a pad layer during the wire-bonding or back-side via-hole forming process, and improving reliability of a device.