Horqin Left Wing Middle Banner, affiliated to Tongliao City, Inner Mongolia Autonomous Region, is located in the northeast of Tongliao City, bordering Shuangliao City, Changling County and Tongyu County respectively in the south, east and north, adjacent to Horqin Right Wing Middle Banner and Zalout Banner in the northwest, and bordering Kailu County, Kerqin District and Kezuohou Banner in the west and south, with a total area of 9811 square kilometers. In 2021, Horqin Left Wing Middle Banner has a total registered population of 514,100, comprising 15 ethnic groups such as Mongolian, Han, Manchu, Hui, Korean, Daur and Ewenki. As of October 2021, Horqin Left Wing Middle Banner has jurisdiction over 1 subdistrict, 11 towns, 5 Su-mu and 1 township.

Kezuo Middle Banner, with a long history and rich cultural heritage, is one of the birthplaces of the Mongolian nation. Qing Chongde first year (1636), set up Horqin left wing flag. In the eighth year of Jiaqing (1803), Lishu County was dislocated. The first year of Daoguang (1821), disregarded the county (Princess Ling City). Xianfeng first year (1851), set up Shuangliao City. Guangxu twenty-four years (1898), in Horqin left wing center Banner set up Siping station. The Republic of China 2 years (1913), dislocated Shuangshan County. In the 3 years of the Republic of China (1914), disregarded Tongliao County. In March 2020, the People's Government of the Inner Mongolia Autonomous Region approved Horqin Left Middle Banner to withdraw from the poverty-stricken flag county list.

In 2021, the GDP of Horqin Left Middle Banner was 13.773 billion yuan, an increase of 3.2%. The added value of the primary industry was 6.139 billion yuan, and that of the secondary industry was 2.133 billion yuan; The added value of tertiary industry is 5.501 billion yuan, and the ratio of tertiary industry structure is 44.57:15.49.39.94