A light guide plate (300) for transmitting light beams from a light source to an LCD (liquid crystal display) includes: an incident surface (301) for introducing light beams into the light guide plate; an emitting surface (303) for uniformly transmitting light beams out from the light guide plate; and a bottom surface (302) opposite to the emitting surface for reflecting the light beams in directions toward the emitting surface. The light guide plate further provides a plurality of concavities (3031) on the emitting surface, for converging the light beams into the LCD. The light guide plate is a relatively simple, single integrated structure, and can obviate the need for a brightness layer in an associated LCD device.