A blue light emitting device includes an electrode layer, a first metal layer, a second metal layer formed between the electrode layer and the first metal layer, and an organic material layer formed between the first metal layer and the second metal layer and including a blue shift light emitting sub-layer. A peak of a first light-emitting spectrum of the blue shift light emitting sub-layer, which ranges within 490-550 nm, is shifted to a peak of a second light-emitting spectrum, which is less than 510 nm, by the surface plasmon coupling between the first metal layer and the second metal layer. A light emitting device is further provided, which is sequentially stacked with a first metal layer, an organic material layer having a blue shift light emitting sub-layer, a second metal layer having a metal portion and an opening portion, an electrode layer, and a light emitting layer doped with a dopant material, to emit white light.