A new growth method of roughed p-GaN has been demonstrated in this paper. First, some crystal seeds of p-GaN are obtained by utilizing low-temperature growth. Then, a p-GaN high-temperature expitaxy layer is grown on it subsequently with a fast growth rate, which will enlarge the roughness degree. Compared with the luminous flux of the conventional light emitting diode with flat p-GaN, the luminous flux is improved by 45%. Meanwhile, it is found that the problems of large reverse current and high forward bias aroused by the low-temperature epitaxy are also solved.