ERS Wind Scatterometer provides capability of the multiple angles by three different look antennas. In this study, the authors have made an evaluation whether the multi-incidence angle observations can help improve surface soil moisture estimations or not. With the theoretical surface backscattering model, i.e., the Advanced Integral Equation Model (AIEM), the authors first simulated a surface backscattering database with a wide range of surface roughness and soil moisture properties at different incident angles. Then,a parameterized surface backscattering model was developed using the simulated database. The newly developed simple model has the roughness function that can be described by a single combined roughness parameter from the commonly used surface roughness descriptors (RMS height and correlation length). This makes it possible for the model to be used as an inversion model.  The development of this simple model, its accuracy, and the inversion test can be demonstrated by using the ground measurements from the Intensive Observation Period (IOP'98) field campaign in 1998 of the Global Energy and Water Experiment (GEWEX) Asian Monsoon Experiment Tibet (GAME/Tibet).