Although Nghi Son economic zone is an integrated economic zone, the priority economic sectors are heavy industry and petrochemical industry. This economic zone includes a non-tariff zone (free trade zone) and a tariff zone. Functional areas in the tariff zone include seaports, residential urban areas, entertainment areas, financial centers, service centers, operating centers, etc. The entire Nghi Son economic zone has an area of 186,118 km², covering 12 wards and communes of Nghi Son town: Xuan Lam, Tinh Hai, Hai Yen, Mai Lam, Hai Thuong, Hai Ha, Nghi Son, Truc Lam, Truong Lam, Tung Lam, Tan Truong, and Hai Binh. On June 17, 2015, the Prime Minister has just issued a decision amending and supplementing a number of articles of the Regulation on operation of Nghi Son economic zone (EZ) (Thanh Hoa province). Accordingly, Nghi Son EZ has a total area of 106,000 ha, including: 66,497.57 ha of land and islands, 39,502.43 ha of water surface (of which: the existing area is 18,611.8 ha, the open area 47,885.77 ha of land and islands, 39,502.43 ha of water surface). The land and island area includes the entire area of the administrative boundary of Nghi Son town: 15 communes and 16 wards (of which 12 wards and communes of Nghi Son EZ exist); 3 communes: Yen My, Cong Binh, Cong Chinh in Nong Cong district; 3 communes: Thanh Tan, Thanh Ky, Yen Lac of Nhu Thanh district, Thanh Hoa province.