A light reflective sheet which comprises a porous resin sheet and a protective layer laminated on at least one surface of the porous resin sheet; which is characterized in the porous resin sheet comprising a polyolefin resin and 100 to 300 parts by weight of a finely powdery inorganic filler with respect to 100 parts by weight of a polyolefin resin; the porous resin sheet being stretched at an area stretch magnification of 5 to 20 times; the light reflectance of the porous resin sheet at a wave length of 550 nm being 95% or more; in which the polyolefin resin is at least one resin selected from the group consisting of high-density polyethylenes, low-density polyethylenes, polypropylenes, ethylene-α-olefin copolymers and ethylene-propylene copolymers; in which the finely powdery inorganic filler is at least one filler selected from the group consisting of barium sulfate, calcium carbonate, titanium oxide, magnesium carbonate, alumina, magnesium hydroxide and zinc oxide; in which the porosity of the porous resin sheet is in the range of from 40 to 70% and the thickness of the porous resin sheet is in the range of from 50 to 500 μm; in which the protective layer has a function as the UV light protective layer; the total light transmittance of the UV light protective layer is 80% or more; the total reflectance of a light beam having a wave length of 550 nm irradiated on the surface of the UV light protective layer of the light reflective sheet is 95% or more; and after the surface of the UV light protective layer of the light reflective sheet has been irradiated with an ultraviolet light of 400 MJ/m2 at 80℃, deterioration ratios of the total reflectances of light beams having wave lengths of 450 nm and 550 nm in the light reflective sheet are both less than 10%, and the light reflective sheet has a stiffness of 50 to 150 mm.