A light reflector, characterized in that it comprises a biaxially stretched film containing a thermoplastic resin and a filler, has an opacity of 95 %, a degree of whiteness of 90 % or more, a reflectivity R<sb>0</sb> of 92 % or more, and an area stretch ratio of 22 to 80, and exhibits a color difference &Dgr;E<sb>H</sb> of 10 or less, after it is irradiated with a irradiation strength of 90 mW/cm<sp>2</sp> by the use of a metal halide lamp located 10 cm apart from it under a circumstance condition of 83˚C and a relative humidity of 50 % for 10 hours. The light reflector does not cause yellowing, which has frequently appeared in the case of a conventional white polyester film reflector, and suffers no color change over a long period of time.
