The retrieval of soil moisture in vegetated areas is often hampered by the influence of vegetation and surface roughness. The polarimetric SAR (PolSAR) can provide complete information related with the electromagnetic scattering characteristics of natural targets, which may contribute to the soil moisture in vegetation covered areas. The objective of this study is to evaluate the potential of Radarsat-2 polarimetric parameters for helping soil moisture retrieval in prairie areas. The ground measurements and satellite data collected from the Ruoergai prairie are used to test and validate the experiments. From the results of soil moisture retrieval, it is validated that the Radarsat-2 polarimetric parameters are sensitive to the variation of the soil moisture. Therefore, the polarimetric parameters are very helpful for estimating the soil moisture in prairie areas.