treaty port, port opened to foreign trade by a treaty. The term is usually confined to ports in those countries that formerly strongly objected to foreign trade or attempted altogether to exclude it. Thus it is used especially in reference to Japan and China. Those countries had admitted trade with the West in the 16th cent. but soon reversed themselves, with Japan permitting only a trickle of Dutch commerce through Nagasaki, and China shutting off all trade until the opening of Guangzhou in 1834. Great Britain, determined to increase commerce, provoked the first of the Opium Wars with China. The Treaty of Nanjing (1842), which restored peace, provided for five treaty ports—Xiamen, Guangzhou, Fuzhou, Ningbo, and Shanghai. As in all the 69 Chinese treaty ports that were finally opened, zones were established for foreign residence that enjoyed extraterritoriality. Most of the ports were on the seacoast or on large rivers. A similar system came into being in Japan after the country was reopened to Western trade by Matthew Perry in 1854. With the abolition of extraterritoriality, the system of treaty ports also disappeared. This occurred in 1899 in Japan but not until 1946 in China.
See J. K. Fairbank, Trade and Diplomacy on the China Coast: The Opening of the Treaty Ports, 1842–1854 (1953, repr. 1969).