A nanostructure semiconductor light emitting device may includes: a base layer having first and second regions and formed of a first conductivity-type semiconductor material; a plurality of light emitting nanostructures disposed on an upper surface of the base layer, each of which including a nanocore formed of the first conductivity-type semiconductor material, and an active layer and a second conductivity-type semiconductor layer sequentially disposed on the nanocore; and a contact electrode disposed on the plurality of light emitting nanostructures, wherein a tip portion of each of light emitting nanostructures disposed on the first region may not be covered with the contact electrode, and a tip portion of each of light emitting nanostructures disposed on the second region may be covered with the contact electrode.