The reflectance factor acquired in laboratory makes a good contribution to spectral library for remote sensing. However, this reflectance factor is a different quantity from that acquired in the field. To bridge the gap between them, the spectral and the spatial characteristics of sunlight and skylight are analyzed. A facility called MHSRS2F is introduced to acquire the anisotropy reflectance in laboratory under the illumination of simulated sunlight and skylight. This reflectance factor is the same quantity as that acquired in field. The amplitude and shape differences between the reflectance factors acquired in laboratory and in field are reduced for 27% and 31% reflectively.