An LED tube lamp includes a lamp tube, two end caps, an LED light strip, a power supply, and a reflective film. At least a portion of an inner surface of the lamp tube is formed with a rough surface, and the roughness of the rough surface is higher than that of the outer surface. Each of the two end caps is coupled to a respective end of the lamp tube by a gel. The LED light strip is disposed on an inner surface of the lamp tube with a plurality of LED light sources mounted on the LED light strip. The power supply is disposed at one or two of the end caps. The power supply is electrically connected to the plurality of LED light sources. The reflective film is disposed on the inner surface of the lamp tube.