A backlight module includes a light guide plate having an incident surface, an emitting surface adjacent to the incident surface, and a reflective surface opposite to the emitting surface. At least one light source is disposed adjacent the incident surface. The light source has a luminescent surface; and at least one reflecting device is disposed adjacent the light source. The reflecting device has a reflective surface facing the incident surface. At least one semi-transmissive and semi-reflective film disposed on the incident surface of the light guide plate. The semi-transmissive and semi-reflective film and the reflecting device together are disposed for cooperatively reflecting some (i.e., a fraction) of the light beams emitted from the light source and redirecting the fraction of the light beams into the light guide plate through the incident surface, distant from the light source.