Abstract: Disclosed herein is an LED lamp for a traffic signal. The LED lamp generally includes a threaded electrode portion, a board holder and a plurality of PCBs. The threaded electrode portions functions to mount a lamp body to a head socket of the traffic signal is an insertion manner. The board holder is mounted on the threaded electrode portion. The PCBs are multi-layered on the board holder and provided with a plurality of LEDs on their entire circumferences. The LEDs fixed on the PCB mounted on an upper portion of the lamp body are vertically mounted so as to face the head of the traffic signal, while the other LEDs fixed on another PCBs are slantingly arranged without overlapping one another so as to face a reflector.