The area of sandy land is extending in China because the natural environment suffers the destruction by the human activity. The estimation of the properties and area of sandy land is an important indicative information for improving the environment. Remote sensing technique can provide scientific and effective data sources using its unique advantage. In this study, we measure the bidirectional reflectance information from sandy land surfaces with different particle sizes and analyze the effect of particle size on the reflection characteristics. Then, a comparison is performed between the measured reflectance and the reflectance of sandy land surface with different particle sizes which is computed based on existing model. The results show that the effect of particle size on the bidirectional reflectance distribution is apparent We also find that the bidirectional reflectance of sandy land surface with different particle sizes can be computed using the bidirectional reflectance model when the difference between measured reflection information and modeled reflection information is small. This study not only defines the effect of particle size on the reflectance from sandy land surface, but also provides valuable reference for estimating the particle size from sandy land surface using remote sensing technique and studying the intrinsic optical property of land surface.