The present invention discloses a nitride semiconductor laser element and fabrication method thereof. The semiconductor laser element comprises: a substrate; a nitride semiconductor layer disposed onthe surface of the substrate which includes an active layer for generating laser and a steam plating prevention layer for preventing the deterioration of the active layer; a strip waveguide formed inthe nitride semiconductor as light limit area; a mirror surface formed by cleaving the nitride semiconductor layer; and a groove formed on at least one side of the strip waveguide and on the mirror surface, the groove formed as the carve area having opening on the surface of the nitride semiconductor layer, and the groove has a bottom surface lies in the vicinity of the steam plating prevention layer. The surface distortion formed on the mirror surface can be reset by the groove disposed in the vicinity of the surface distortion start position, and thereby preventing the surface distortion formed in the strip waveguide of the emitted laser.