Abstract: The Okinawa Trough is a young, long and narrow marginal basin in the convergent zone on the northwest edge of the Pacific Ocean Plate, In this paper it is shown that the Okinawa Trough first experienced depression, then faulting and spreading, on the basis of the data obtained from the sea floor topograph, the sediment composition, the characteristics of gravity and magnetic anomalies, the profiles from reflection and refraction seismic survey, the distribution of the volcanoes and earthquake focuses in the Trough, and the geological and geophysical data obtained from both sides of the Trough—the Ryukyu Island Arc and the continental shelf marginal upfold zone.