Jianhu county belongs to Yancheng City, Jiangsu Province. 194 1 September, Yancheng county, Jianyang county. 195 1 July, renamed Jianhu county.

Jianhu county is located in the northeast of Jiangsu Province and the middle and west of Yancheng City. The county seat is slightly mandarin fish-shaped, with its head facing southwest and its tail facing northeast. Geographical coordinates are 3316 ′ ~ 33 41′ north latitude and 0/9 32 ′ ~120 05 ′ east longitude. It is about 43.7 kilometers long from north to south and 48.7 kilometers wide from east to west. Total area 1 154 km2, of which the water area accounts for 19.58%. Jianhu Lake is located in the northern edge of subtropical zone, with obvious temperate monsoon climate, abundant sunshine, an average frost-free period of 2 12 days, abundant rainfall, annual average precipitation 1020. 1mm and annual average temperature 14℃. Suitable for crop growth. Traditional products include "rice, wheat, firewood, lotus root" and "fish, crab, turtle, shellfish and shrimp", which is known as the hometown of "rice, rice and soup fish". Now it is one of the national key commodity grain bases.

The whole territory is flat and fertile, with criss-crossing ditches and rivers, dotted with polder areas, surrounded by long dikes and shaded by trees, showing a water town scenery. There are more than 5666.67 hectares of beaches in Xihu District, and aquatic products are extremely rich. The provincial tourist areas "Jiulongkou" and "Floating Pier" are strange, mysterious and famous, with excellent scenery. It has the reputation of "West Lake", which makes people linger.