The present invention provides a light guide panel and a backlight module using the light guide panel. The light guide panel is disposed corresponding to a light source module of the backlight module. The light guide panel mainly comprises a plate, a plurality of microstructures and a plurality of protrusions. The plate is disposed close to the light source module and includes a microstructure surface. The microstructures and the protrusions are disposed on the microstructure surface, and the heights of the protrusions are greater than those of the microstructures, and a plurality of the microstructures are disposed between the adjacent protrusions.