An LED lamp includes an optical part, a heat dissipation member and an electric part. The optical part includes a hollow light penetrable tube and an LED module received in the tube. The heat dissipation member is received in the tube to mount the LED module thereon. The electric part include a circuit board and a rechargeable battery arranged in the tube, and two end covers arranged at two opposite ends of the tube. The LED module is provided with at least one first LED and at least one second LED. The at least one first LED and the at least one second LED cooperatively function as a main light source to provide normal illumination when an external AC power source is supplied normally. The at least one second LED independently function as an auxiliary light source to provide emergency illumination when the external AC power source is interrupted.