The backlight assembly includes a lamp unit, a light guide plate and a receiving container. The light guide plate includes a light exiting surface, a light reflecting surface facing the light exiting surface, and side surfaces. The receiving container includes a frame plate and sidewall protruding from an outer edge of the frame plate to form a receiving space for receiving the lamp unit and the light guide plate. The first distance between an inner surface of the sidewall and an outer surface of the light guide plate at a first region is greater than a second distance between the inner surface of the sidewall and the outer surface of the light guide plate at a second region. The light guide plate is more spaced apart from the sidewall at the corners where much noise was made, in a general backlight assembly, so that the noise is reduced.