A light emitting diode (LED) includes a substrate, a buffer layer and an epitaxial structure. The substrate has a first surface with a patterning structure formed thereon. The patterning structure includes a plurality of projections. The buffer layer is arranged on the first surface of the substrate. The epitaxial structure is arranged on the buffer layer. The epitaxial structure includes a first semiconductor layer, an active layer and a second semiconductor layer arranged on the buffer layer in sequence. The first semiconductor layer has a second surface attached to the active layer. A distance between a peak of each the projections and the second surface of the first semiconductor layer is ranged from 0.5 μm to 2.5 μm.