An LED lamp includes a rectifier; an inverted cup shaped heat sink comprising spaced heat radiating members projecting upward, and spaced hollow cylindrical heat radiating elements arranged around the heat radiating members; a mounting plate fastened between the rectifier and the heat radiating members; L-shaped heat conduction members each having a longitudinal part inserted through the heat radiating element and a lateral part engaged with bottom of the heat sink; and a circuit board secured to the bottom of the heat sink to fasten the lateral parts of the heat conduction members, the circuit board comprising LEDs each electrically connected to the rectifier and being in contact with the lateral parts of the heat conduction members. The heat sink further includes first, second, and third heat radiating plates arranged around the heat radiating element.