A light guide plate includes a main body, a main reflective structure and an auxiliary reflective structure. The main reflective structure has a first included angle and a second included angle with respect to a bottom surface of the main body. The auxiliary reflective structure is adjacent to the main reflective structure and has a third included angle and a fourth included angle with respect to the bottom surface. A height difference between the main reflective structure and the auxiliary reflective structure ranges between 1.5 micrometer and 5 micrometer, and a bottom width of the auxiliary reflective structure on the bottom surface is smaller than a bottom width of the main reflective structure on the bottom surface. A liquid crystal display is also disclosed herein.