Abstract: The time-variant fractal surface is adopted to describe regional dynamical feamre of terrain and ocean surface. Under three rational assumptions on electromagnetic scattering, the time domain property of scattering field is analyzed qualitatively by applying Kirchhoff solution, and the fractal model of clutter from terrain and ocean surface is deduced. The amplitude distribution, power specmim and parameters of the returns are discussed in brief Theoretical analysis and simulated results prove that the fractal model matches the clutters from terrain and ocean suthee effectively.