Abstract: A light emitting diode (LED) includes a heat dissipation structure characterized by having a heat dissipating fluidic coolant filled in a hermetically sealed housing where at least one LED chip mounted on a metallic substrate is dwelled inside. The heat dissipation structure is configured with a metallic wall erected from the metallic substrate, which is used to hold a transparent cap of the sealed housing in correct position. Furthermore, the erected wall surrounds in proximity with the at least one LED chip, so that the joule heat generated therefrom can be quickly spread out, through the heat dissipating fluidic coolant, to the erected wall, and then diffused along the wall down to the metallic substrate which adjoins with a larger external heat sink for draining the heat, thus preventing the at least one LED from overheating.