|Country||People's Republic of China|
|Time zone||UTC+8 (China Standard)|
In 411, the western part of then Hailing (Taizhou) was separated from the county to create Rugao county, which named after a coastal village. During Sui dynasty, the county was merged into Ninghai county. Restored in 952, the county was transferred to then Tongzhou in 1724. Around the 1930s, Rugao was the most populous county in then Jiangsu province. Two county governments of the New Fourth Army were established in the then county: Ruxi (literally Western Rugao) and Rugao (1940–5, was renamed as Rudong by the CPC in November 1945 ), while the Tongzhou-Yangzhou Canal marked the boundary between the two regions, during the Second Sino-Japanese War. Ruxi succeed to the designation Rugao in 1945, the reshuffling of territory came true only in January 1949, when the CPC totally controlled the area. On 1 June, 1990, with approval of the State Council, Rugao was turned into a county-level city, which went into effect in 1991.