A display device includes a display panel and a backlight module. The display panel has an active area. The backlight module includes a light guide plate, a light converting film and a side-emitting light source. The light guide plate includes a plurality of first diffusion dots and a plurality of second diffusion dots, wherein the first diffusion dots are arranged corresponding to the active area, the second diffusion dots are arranged corresponding to a periphery of the active area, and a diameter of the second diffusion dot is smaller than a diameter of the first diffusion dot. The side-emitting light source is used for emitting a first color light into the light guide plate. The first diffusion dots and the second diffusion dots guide the first color light to the light converting film uniformly. The light converting film converts the first color light into a second color light.