The present invention provides a light diffusing polycarbonate resin composition including a polycarbonate resin containing a polycarbonate copolymer which comprises a repeating unit represented by the general formula (I) shown below and a repeating unit represented by the general formula (II) shown below, which has a content of the repeating units of the general formula (II) of 1 to 30% by mass and which has a viscosity value of 30 to 71, and (B) a light diffusing agent compounded therein in an amount of 0.01 to 10 parts by mass per 100 parts by mass of the polycarbonate resin. The light diffusing polycarbonate resin composition and a light diffusing plate thereof show improved fluidity during molding and have excellent heat resistance, dimensional stability, luminance and color tone.