The regression expressions of principal forces in th'e motion equation were recalculated after enlarging of sizes of the samples relative to the Philosophy of the statistical-dynamic model (SD-75) for typhoon track forecast. Then a test on the operational forecasts of typhoon track in the 1987 typhoon season was carried out, using the revised model (called SD-85).The results indicate that the later is more advanced than the former in respect of prodictive characteristics.