There is provided a semiconductor light emitting device including a first conductivity-type semiconductor base layer and a plurality of light emitting nanostructures disposed to be spaced apart from one another on the first conductivity-type semiconductor base layer, each light emitting nanostructure including a first conductivity-type semiconductor core, an active layer, an electric charge blocking layer, and a second conductivity-type semiconductor layer, respectively, wherein the first conductivity-type semiconductor core has different first and second crystal planes in crystallographic directions.