Ruijin (Chinese: 瑞金; pinyin: Ruìjīn) 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.
It was an early center of Chinese communist activity and developed a reputation as cradle of the Chinese Communist Revolution. In the late-1920s, the Nationalists forced the Communists out of the Jinggang Mountains, sending them fleeing to Ruijin and the safety of its relative isolation in the rugged mountains along Jiangxi-Fujian border. In 1931, Mao Zedong founded the Chinese Soviet Republic (CSR) with Ruijin as its capital; it was called Ruijing by the CSR. The Communists withdrew in 1934 on the Long March after being surrounded again by the Nationalists.