An LED backlight module includes an LED light plate, a diffusion plate, a brightening film, an MOP film, and a QBEF film. The LED light plate includes a driving circuit, a substrate, and LED devices on the substrate. Each LED device includes a transparent LED frame, an LED chip disposed on a bottom portion of the transparent LED frame, and a packaging glue layer formed inside the transparent LED frame and covering the LED chip. A diffusion agent is distributed in the packaging glue layer.