An LED tube lamp includes a lamp tube, an LED light bar disposed inside the lamp tube with a plurality of LED light sources provided on the LED light bar, a diffusion film layer disposed inside the lamp tube and configured to transmit the light emitted from the LED light sources, and a reflective film layer disposed on an inner circumferential surface of the lamp tube. The reflective film layer is configured to partially occupy the inner circumferential surface of the lamp tube along a longitudinal direction and a circumferential direction of the lamp tube, and the diffusion film layer is a sheet disposed to cover the LED light sources without making direct contact with the LED light sources.