There are disclosed a group III nitride nanorod light emitting device and a method of manufacturing thereof. The group III nitride nanorod light emitting device includes a substrate, an insulating film formed on the substrate, and including a plurality of openings exposing parts of the substrate and having different diameters, and first conductive group III nitride nanorods having different diameters, respectively formed in the plurality of openings, wherein each of the first conductive group III nitride nanorods has an active layer and a second conductive semiconductor layer sequentially formed on a surface thereof.