In this paper, the Bistatic scattering coefficient from one - dimension Gaussian perfect conductor random rough surface is computed by the Moment method in Dirichlet boundary condition, and the basis function is taken as the pulse function and weighting function in the point matching method. A tapered incident wave is applied. By this method, two different spectrums in rough surface are analyzed. The results prove that the simulation of rough conducting surface with Gaussian surface is better in effect, which is a good method of modeling in electromagnetic environment.