A light guide plate includes a main body portion and inclined light guide portions having at least one recess. The main body portion has a first light incident surface, a bottom surface that is adjacent to the first light incident surface, and a light emitting surface that is opposite to the bottom surface. The inclined light guide portions disposed on the main body portion have a second light incident surface and at least one inclined surface. The second light incident surface is connected to the first light incident surface of the main body portion. The inclined surface is connected to the light emitting surface of the main body portion. At least one recess is formed between the inclined light guide portions. In addition, a wedge-shaped body can further be formed between the main body portion and the inclined light guide portions.