Changzhou is a prefecture-level city in southern Jiangsu, China. It lies on the southern bank of the Yangtze River and borders Nanjing, the provincial capital, to the west; Zhenjiang to the northwest; Wuxi to the east; and Zhejiang province to the south. It was previously known as Yanling, Lanling, and Jinling.
The population of the Changzhou Municipality was 5,278,121 at the 2020 census. The city is the birthplace of Zhou Youguang, who created the pinyin romanization system.