Abstract: An LED bulb includes: a circuit board having opposite first and second surfaces; a plurality of LEDs disposed on the first surface; and a heat dissipating structure having a heat dissipating board, wherein the heat dissipating board has opposite third and fourth surfaces, the third surface is attached to the second surface of the circuit board, and a plurality of heat dissipating bumps is disposed on the fourth surface and gradually decreases in length from the center toward the periphery of the fourth surface to thereby facilitate air convection around the heat dissipating bumps, thus improving the overall heat dissipating efficiency so as to increase the light emitting efficiency and lifetime of the LED bulb.