As part of
Suihua, human settlement began in the
Paleolithic era. The
Sushen people were the most prevalent, but the south and southwestern areas that now make up modern-day Zhaodong,
Mingshui,
Qinggang, and
Anda were also settled by the
Yemaek through the
Western Zhou and
Western Han dynasty. During the
Sui and
Tang dynasties, the
Mohe people lived in the area of modern-day Zhaodong. During the
Liao dynasty, Zhaodong was part of
Liaoyang Prefecture. In 1908, Zhaodong Sub-prefecture was created from
Zhaozhou Sub-prefecture. Zhaodong became an in November 1912, then a county in July 1914. Between 1898 and 1940, the namegiving settlement, Zhaodong, now an administrative town under the city, was known as Mangou (满沟), after the Mongols of Rear Gorlos Banner (
Zhaoyuan), who used the area at Zhaodong as
grazing fields, the name being popularized from the historic railway station of the same name. It also developed the nickname Tiancaogang (甜草岗; ) for the wild growing
liquorice in the hillside. Zhaodong was formed as a second-class county of Suihua in 1929 by the , following the abolishment of the
circuit system. In July 1937, Zhaodong County government moved its headquarters from to Mangou, which prompted the name change in May 1940 to match the county. During the
Chinese Civil War, Zhaodong was split off from Heilongjiang Province to become a directly administered county under
Songjiang Province. With the establishment of the People's Republic of China in 1949, Zhaodong was returned to Heilongjiang. In 1956, following the formation of , the counties of Zhaodong, Zhaozhou, and Zhaoyuan were the only subdivisions formerly under Suihua to remain under direct provincial control. Zhaodong came under jurisdiction of Harbin in August 1958, then in May 1960. Between June 1965 and December 1982, Zhaodong County returned to administration under Suihua via different offices and committees before Suihua was reduced in jurisdiction to a county-level city. Zhaodong became a county-level city in September 1986 and became administered by Suihua again in 2000, when the latter was made a prefecture-level city. == Economy ==