Jianhu County is under the jurisdiction of Yancheng City, Jiangsu Province. Located in the hinterland of Lixia River in northern Jiangsu Province, it is under the jurisdiction of Yancheng City. The geographical location is 33 ° 16 ′ - 33 ° 41 ′ N and 119 ° 33 ′ - 120 ° 05 ′ E. The total area of the county is 1154 square kilometers. According to the seventh census data, as of 0:00 on November 1, 2020, the permanent population of Jianhu County is 609346.

Jianhu County is named after the initials of Jianyang and Huduo (now near the lake) towns. In September 1941, Yancheng County was divided into counties and Jianyang County was established. In July 1951, it was renamed Jianhu County. It is a national garden county, a sub-county for the protection and utilization of revolutionary cultural relics, a state-level seed production county, and a hometown of Chinese folk culture and art.

In 2020, the GDP of Jianhu County will reach 57.19 billion yuan, up 3.5%. The general public budget revenue was 3.166 billion yuan, up 5%.