By using the Monte Carlo method and numerical finite elementapproach, bistatic scattering from the fractal and Gaussian rough surfaces is studied. The difference between these two surfaces and their functional dependence on the surface parameters are discussed. Angular variation of bistatic scattering from the fractal surface is very significant, even for fairly smooth surface, whilst scattering from the Gaussian rough surface tends to the specular reflection. The slope of angular variation is linearly related with the fractal dimension. If an electrically_large target is placed over the rough surface, the fractal dimension inverted from bistatic scattering would be reduced. As the surfaces become very rough, scattering from different fractal and Gaussian surfaces would be not identified.