Abstract: The scattering properties and regularity of high power microwave propagation on the jungle-ground are analyzed with finite difference time domain (FDTD) method. The scattering properties at different incident angles are obtained, and the relationship between jungle scattering coefficient and grazing angle are comparatively analyzed with analytic and numerical methods. The theoretical analysis and numerical computation indicate that the scattering coefficient curve has a Brewster angle. Larger electrical parameters of topography lead to smaller Brewster angle. When the grazing angle is less than the Brewster angle, the scattering coefficient decreases with the grazing angle increasing; when the grazing angle is greater than the Brewster angle, the scattering coefficient increases with the