Provided is a nitride semiconductor light emitting device including p-type nitride semiconductor layer, an n-type nitride semiconductor layer, and an active layer formed therebetween. A contact layer is positioned between the p-type nitride semiconductor layer and a p-side electrode. The contact layer includes a first p-type nitride layer having a first impurity concentration to form ohmic contact with the p-side electrode and a second p-type nitride layer having a second impurity concentration, the second impurity concentration having a concentration lower than the first impurity concentration.