Abstract: Based on the conception of rainfall rate adjustment factor obtained from exponential rain cell(So called EXCELL) model, and by analyzing the rain attenuation measured data in ITUR SG3 database, a formula for the rainfall rate adjustment factor is proposed. The coefficients in the rainfall rate adjustment factor have been regressed based on the experimental data in ITUR database, then, a new rain attenuation prediction model for the terrestrial lineofsight systems is proposed in which the full rainfall rate distribution has been utilized. The comparison results with other models shows that this model get better predict result than other models with full rainfall rate distribution, and get nearly same accuracy as the ITUR model with conversion，this model is also simple for use.