The invention provides an LED package capable of effectively releasing heat emitted from an LED chip out of the package and a fabrication method thereof. For this purpose, at least one groove is formed on an underside surface of the substrate to package the LED chip and the groove is filled with carbon nanotube material. In the LED package, a substrate having at least one groove on the underside surface is prepared. A plurality of electrodes are formed on a top surface of the substrate. Also, at least the one LED chip is mounted over the substrate to have both terminals electrically connected to the upper electrodes. In addition, carbon nanotube filler is filled in the groove of the substrate.