A LED lamp includes: a plurality of substrates juxtapositionally formed as multiple layers, each substrate having a plurality of light emitting diodes (LEDs) mounted thereon, whereby upon generation of heat by the LEDs when lit up, each substrate will form as a heat-dissipating plate in-situ in order that the multiple-layer substrates will instantly effectively dissipate the heat produced from the LEDs of the lamp outwardly for preventing deterioration of the illumination quality of the LED lamp.