Haiyan County (simplified Chinese: 海盐县; traditional Chinese: 海鹽縣; pinyin: Hǎiyán Xiàn) is a county under the administration of Jiaxing City, Zhejiang province, China.
Its area is 503 km2 (194 sq mi). Population is 370,000. Postal code: 314300.
The county government is located on 118 Zaoyuan Middle Rd, Wuyuan town.
In August 2010, Haiyan was selected to house the 'Nuclear City'. China will reportedly spend some €130 billion over the next ten years on developing the 130 square-kilometre Haiyan Nuclear City, which will be needed by local industry. By 2014, nine nuclear power plants should be in operation, with electrical generating capacity of around 6300 MWe, which will help reduce the country's carbon footprint.
In September 2015, Six Flags and Riverside Group announced that they will build the first international Six Flags theme park in Haiyan County, Zhejiang.