A direct-type backlight module includes a light-guide plate. The light-guide plate has a first surface and a second surface opposite the first surface. The first surface has at least one first groove. The backlight module may also include at least one light source. The light source corresponds to the first groove so that light emitted from the light source is reflected by the first groove. One or more optical films may be disposed on the first surface of the light-guide plate and a reflector may be disposed below the second surface of the light-guide plate. With the light-guide plate in place, the overall thickness of the backlight module is reduced, and the lamp mura is avoided.