Abstract: Based on the geologic and geophysical data of the Okinawa Trough,the reflection of two times of extension during the forming of the Okinawa Trough in the thickness of lithosphere,the thickness of Earth's crust,the heat flow value of Earth's surface,tectonic subsidence and thermal subsidence as well as geotemperature field is calculated by a two-layer extension model.Besides,the interrelation among parameters is discussed,and effect of each type of parameters on the calculated results is estimated.These results have provided important clues for understanding the extension history of the Okinawa Trough.