Abstract: A relational backscattering coefficient model based on the modified composite sea clutter model has been built in order to analyze the impact of oceanic environment on radar backscattering characteristics. The main scattering form is specular return under the high-grazing angle condition , and Bragg scattering under the low-grazing angle condition. Improvements have been made in the directional ocean wave spectrum part of Bragg scattering, considering the difference of backscattering coefficient between upwind and downwind conditions. With the model, simulation has been made in different incident conditions. The results indicate that the characteristics of radar backscatter would be very sophisticated when the sea surface is involved. Oceanic factors like wind speed ,wind direction, waves, rainfall, slick can have some effects on the backscattering coefficient. Furthermore, wind speed and significant wave height both have the largest effect on backscattering coefficient, and wind direction takes second place, then rainfall, and slick is the least influential factor listed here.