The East China Sea is located between China to the west, Taiwan to the south, South Korea to the north and Japan to the east. Its area is about 1.25 million km². Large areas of this sea are shallow shelf seas with an average depth of about 275 meters. Towards the southeast, the Okinawa Trench forms the deepest point at 2719 m.
Riparian countries are China, Japan, South Korea and Taiwan. The Chinese Yangtze River, the longest river in Asia, whose headwaters lie in the highlands of Tibet, carries an annual average of 31,900 m³ of water per second and flows into the East China Sea.
Because of the extensive oil deposits, the bordering states are in dispute. The conflict over ownership of the Socotra Rock, which is claimed by both South Korea and the People's Republic of China, is a case in point.