The present invention discloses an LED structure, wherein an N-type current spreading layer is interposed between N-type semiconductor layers to uniformly distribute current flowing through the N-type semiconductor layer. The N-type current spreading layer includes at least three sub-layers stacked in a sequence of from a lower band gap to a higher band gap, wherein the sub-layer having the lower band gap is near the substrate, and the sub-layer having the higher band gap is near the light emitting layer. Each sub-layer of the N-type current spreading layer is expressed by a general formula InxAlyGa(1-x-y)N, wherein 0≦x≦1, 0≦y≦1, and 0≦x+y≦1.