A light diffusing plate is provided to improve heat-resisting property and moisture-resisting property by forming a surface layer on one surface or both surfaces of a base material layer. The light diffusing plate includes a base material layer containing a first base resin made of polycarbonate resin and polystyrene resin, and a surface layer formed on one surface or both surfaces of the base material layer. The surface layer contains a second base resin made of styrene-acrylic based copolymer resins and fluorine based resin. The ratio of first base resin is 9:1 to 1:9 by weight mixture of polycarbonate resin and polystyrene resin, and the ratio of second base resin is 6:4 to 1:9 by weight mixture of acrylic monomer and styrene monomer.
