The snow albedo which is influenced by the snow grain size, plays an important role in regional or global radiation balance and climate change. The degree of influence depends on the microphysical and optical properties of snow. In this paper, the influence of snow grain size on sensitivity of snow bidirectional reflectance was simulated and analyzed by the radiative transfer equation based on the studies of snow optical characteristics in 550 nm, 1030nm and 1 640 nm. The results indicate that the near-infrared channel 1 030 nm is the sensitive wavelength to retrieve snow grain size. In this band, snow bidirectional reflectance changes significantly when grain size and view angle change. This study provides the theoretical basis for retrieving snow grain size with the multi-angular remote sensing data.