A light guide plate includes an incident face, a bottom surface, a main reflective structure and an auxiliary reflective structure. The bottom surface is connected to the incident face. The main reflective structure is disposed on the bottom surface and has a first and a second inclined surface. The auxiliary reflective structure is disposed on the bottom surface and has a third and a fourth inclined surface. The auxiliary reflective structure and the main reflective structure have an interval therebetween, in which the interval ranges between 0.2 micrometer and 0.5 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.