Disclosed is a liquid crystal display (LCD) device capable of minimizing the occurrence of light leakage at peripheral regions of protrusions by maximizing a distance between an image display region and the protrusions, by forming the protrusions at one or more corners of the light guide plate. The LCD device comprises: a light guide plate having protrusions at one or more corners thereof; a main support having fixing grooves formed at one or more corners thereof corresponding to the corners of the light guide plate, the locking grooves for coupling the protrusions of the light guide plate; an LC panel for displaying an image by using light emitted from the light guide plate; an optical source having one or more light emitting diodes (LEDs) for irradiating light to the light guide plate; a reflection sheet for reflecting light emitted from a rear surface of the light guide plate to the light guide plate; and one or more optical sheets disposed between the light guide plate and the LC panel.