A backlight apparatus includes a light-guiding plate, two first light-emitting members and two second light-emitting members. The light-guiding plate has a first edge and a second edge parallel to the first edge. The light-guiding plate has two first recesses and two second recesses. The two first light-emitting members are disposed in the two first recesses respectively, and the two second light-emitting members are disposed in the two second recesses respectively. The two first light-emitting members are rotated at a predetermined angle respectively, such that first light-emitting axes of the two first light-emitting members tend toward the first edge and the second edge of the light-guiding plate respectively. Besides, second light-emitting axes of the two second light-emitting members are parallel to the first edge and the second edge of the light-guiding plate.