Disclosed are a light emitting device, a method of manufacturing the light emitting device, a light emitting device package and a lighting system. The light emitting device includes a silicon substrate; a nitride buffer layer on the silicon substrate; and a gallium nitride epitaxial layer on the nitride buffer layer, wherein the nitride buffer layer includes a first nitride buffer layer having a first aluminum nitride layer on the silicon substrate and a first gallium nitride layer on the first aluminum nitride layer.