A backlight module includes a light-shielding plate, a light guide plate, a first light-emitting element, and a second light-emitting element. The light-shielding plate has a first light transmissive portion. The light guide plate has a first light-emitting dotting area. The first light-emitting dotting area includes a plurality of first dots unevenly distributed within a range of the first light-emitting dotting area. The first light-emitting element and the second light-emitting element emit light toward the first light-emitting dotting area. The light guide plate has a light-emitting surface in a generally rectangular shape. The light guide plate has a first long axis direction extended parallel to a long side on the light-emitting surface. The first light-emitting element has a second long axis direction. An angle between the first long axis direction and the second long axis direction is an acute angle.