A light emitting diode includes: a substrate of front and back main surfaces; a V-shaped groove, which has a reflecting surface, formed over front surface of the conductive substrate; a light-emitting epitaxial layer, the margin of which has its vertical projection between the bottom and the inner margin of the V-shaped groove, formed over the substrate, so that light emitted from the light-emitting epitaxial layer margin is incident to the mirror surface of the V-shaped groove and emits outwards. This structure can effectively improve extraction efficiency of device and control path of light at peripheral region of the light-emitting epitaxial layer.