Korea Bay, inlet that forms the northeastern arm of theYellow Sea between the Liao-tung Peninsula (inLiaoning province),China, and westernNorth Korea.

Korea Bay receives three of the major rivers of North Korea—the Yalu (which rises onMount Paektu and forms much of the China–North Korea border), the Ch’ŏngchŏn, and the Taedong—in addition to a number of China’s smaller rivers. The bay is relatively shallow, seldom reaching depths greater than 164 feet (50 m). Its tidal range of 20 to 40 feet (6 to 12 m) is unusually high. Many wide sandbars extend along the coast, and the bay contains a number of rocky islands, including North Korea’s Ch’o, Sŏk, and Sinmi islands and China’s Ch’ang-shan and Ta-ch’ang-shan islands. The major ports on Korea Bay are the North Korean cities of Namp’o andSinŭiju and China’s Lü-shun andTan-tung.