A nitride-based semiconductor light emitting device with improved characteristics of ohmic contact to an n-electrode and a method of fabricating the same are provided. The nitride-based semiconductor light emitting device includes an n-electrode, a p-electrode, an n-type compound semiconductor layer, and an active layer and a p-type compound semiconductor layer formed between the n- and p-electrodes. The n-electrode includes: a first electrode layer formed of at least one element selected from the group consisting of Pd, Pt, Ni, Co, Rh, Ir, Fe, Ru, Os, Cu, Ag, and Au; and a second electrode layer formed on the first electrode layer using a conductive material containing at least one element selected from the group consisting of Ti, V, Cr, Zr, Nb, Hf, Ta, Mo, W, Re, Ir, Al, In, Pb, Ni, Rh, Ru, Os, and Au.