A light emitting diode includes a substrate, a number of light emitting units formed on the substrate, and an insulating layer. Each light emitting unit includes a first electrode layer, a number of light emitting nanowires and a second electrode layer. Each light emitting nanowire includes a zinc-oxide-nanowire buffering segment extending from the first electrode layer, an N-type gallium nitride nanowire segment and a P-type gallium nitride nanowire segment. The N-type gallium nitride nanowire segment is interconnected between the zinc-oxide-nanowire buffering segment and the P-type gallium nitride nanowire segment. The P-type gallium nitride nanowire segment has a distal portion embedded in the second electrode layer. The insulating layer is formed on the substrate and the first electrode layer. The light emitting nanowires is embedded in the insulating layer and insulated from each other.