The Chinese Soviet Republic (CSR) was a state within China, proclaimed on 7 November 1931 by Chinese Communist Party (CCP) leaders Mao Zedong and Zhu De in the early stages of the Chinese Civil War. The discontiguous territories of the CSR included 18 provinces and 4 counties under the communists' control. The CSR's government was located in its largest component territory, the Jiangxi Soviet. Due to the importance of the Jiangxi Soviet in the CSR's early history, the name "Jiangxi Soviet" is sometimes used to refer to the CSR as a whole. Other component territories of the CSR included the Northeastern Jiangxi, Hunan-Jiangxi, Hunan-Hubei-Jiangxi, Hunan-Western Hubei, Hunan-Hubei-Sichuan-Guizhou, Eyuwan, Shaanxi-Gansu, Sichuan-Shanxi, and Haifeng-Lufeng Soviets.

Ruijin is a county-level city of Ganzhou in the mountains bordering Fujian Province in the south-eastern part of Jiangxi Province. Formerly a county, Ruijin became a county-level city on May 18, 1994.