Two large Cenozoic sedimentary basins comprise the East China Sea: the East China Sea Shelf Basin (ECSSB) and the Okinawa Trough Basin (OTB). The ECSSB formed between the Late Cretaceous or Paleocene to Quaternary. This basin has a sedimentary sequence more than 12 km thick. In contrast, the OTB formed by back-arc spreading since mid-Miocene. The general tectonic pattern of the East China Sea is characterized by east-west zonation and north-south differentiation in tectonic evolution, sedimentary facies distribution, and magmatism. Five regional unconformities can be observed on seismic sections corresponding to five major tectonic movements. The most significant of these unconformities are of Eocene-Oligocene, middle Miocene-Pliocene, and Pliocene-Pleistocene age. The fi st commercial discovery in the East China Sea was drilled in 1983. Since then a number of other wells have also been successful. Future prospects for oil and gas in the East China Sea appear good.