The historical opening of five Chinese ports to foreign trade following the 1842 [[南京条约|南京條約|nan2 jing1 tiao2 yue1]]; the ports included [[广州|廣州|guang3 zhou1]], [[福州|福州|fu2 zhou1]], [[宁波|寧波|ning2 bo1]], [[厦门|廈門|xia4 men2]], and [[上海|上海|shang4 hai3]]

A port or city specifically opened for foreign trade, especially those forced open by foreign powers during the Qing Dynasty; trading port.

A commercial treaty or trade pact between nations regarding economic relations and navigation.

A port along a river or coast used for trade; specifically refers to a treaty port.