In this paper, we approximated gonio radiance properties of the surface reflection component of paper sheets by BRDF model, which is required in the digital image archive system recording the specimens of forensic document examination. Surface reflection component was selectively acquired by measuring the paper sheets processed with gold evaporation. Gonio radiance factor of three kinds of gold-coated paper sheets were approximated by the TSL model, which is the linear combination of two BRDF models, Torrance-Sparrow model and Lambert model. Relative gonio properties of each sample were well depicted by the TSL model, however a large deviation occurred in the specular reflection geometry for glossy paper. The RMSE between the measurement and the approximation by the TSL model was under 2% of the range of measured value. The roughness parameter in Torrance-Sparrow model corresponded with the state of surface roughness, and also the ratio between Torrance-Sparrow model and Lambert model showed the difference of material characteristics between samples. Therefore, the TSL model was considered to be effective as a BRDF model approximating the gonio radiance properties of surface reflected light from paper sheets.