Abstract: To investigate electromagnetic scattering from layered rough surface by method of moment, a direct domain decomposition method is used to derive electromagnetic integral equation of layered rough surface. Combining with wave equation and Green's function, electromagnetic integral equations of layered rough surface are obtained by applying Green's theorem to each space divided by rough surface. Then integral equation is discretized using method of moment. Angular distributions of electromagnetic scattering coefficient from ground covered with snow are obtained with numerical calculation, in which snow surface and ground are described with 1D band-limited Weierstrass fractal spectrum and Monte Carlo method. Accuracy of the domain decomposition is demonstrated by finite difference time domain results. Through analyzing scattering coefficient that varies with parameters of snow and ground, medium parameters of snow and soil, parameters of incident wave, the complete scattering characteristics are obtained.