A backlight module including a housing, a first reflector plate, a light guide plate, a second reflector plate and at least one light bar is provided. The first reflector plate is disposed on a bottom of the housing, and the light guide plate is disposed within the housing. The light guide plate includes a first optical surface, a second optical surface and a light emitting surface, and the first optical surface is adjacent to the first reflector plate. The second reflector plate is adjacent to the second optical surface of the light guide plate. The light bar is disposed between the first reflector plate and the light guide plate, and the light bar is opposite to the second optical surface.