Abstract: A backlight module comprises a light emitting element and a light guide panel having a light output surface in which the light output surface is with a first side, a second side, a through hole, a recess and plural microstructure rows. The microstructure rows are arranged on the light output surface, and the extending direction thereof is parallel to the extending direction of the first side. The through hole is installed between any two adjacent microstructure rows. The light emitting element is disposed in the recess in a central zone of the light output surface, and arranged to emit lights towards the second side. One major light emitting axis of the light emitting element deviates from the through hole.