Large-area porous single crystal gallium nitride micro/nanotube arrays were prepared by a simple method using zinc oxide arrays as the template. This is the first synthesis of such a type of porous GaN micro or nanotubes. The inner diameters of these tubes could be accurately controlled by varying the diameters of zinc oxide micro/nanowires. The area of these micro/nanotube arrays could be achieved at a desired large value by changing the area of zinc oxide micro/nanowire arrays. The deoxidization of zinc oxide at the beginning of the epitaxial growth is the key step to obtain these porous single crystal micro/nanotubes. With large specific surface area, these tubes would be advantageous in potential photocatalysis, nanoelectronic, optoelectronic and biochemical-sensing applications.