We establish the relation expression between scattering fields and illuminating fields in local coordinate system.Simulating horizontally polarized and vertically polarized incident waves

we can get all elements of scattering matrix.The result can be used to numerically simulate the distribution of the fully polarized backscattering RCS(Radar Cross Section) of sea fractal surface.The changing of fully polarized backscattering RCS with different directions of flying direction are simulated.The result shows that the distributions of the fully polarized backscattering RCS of different of flying direction are identical among the four sorts of polarization.Our model is the base of fully polarizing radar imaging.