A fabrication method of light emitting diode is provided. A first type doped semiconductor layer is formed on a substrate. Subsequently, a light emitting layer is formed on the first type doped semiconductor layer. A process for forming the light emitting layer includes alternately forming a plurality of barrier layers and a plurality of quantum well layers on the first type doped semiconductor layer. The quantum well layers are formed at a growth temperature T1, and the barrier layers are formed at a growth temperature T2, where T1