Ansai (simplified Chinese: 安塞区; traditional Chinese: 安塞區; pinyin: Ānsāi Qū) is a district of the city of Yan'an, Shaanxi province, China. It has a total area of 2,951.3 km² (1,139.5 sq mi) and a population of 172,900 people. Part of the Loess Plateau, the district has an average elevation of 1,371.9 metres (4,501 ft). Its postal code is 717400, and its Serial Number is 610624.

Ansai District administers three subdistricts and eight towns.

Ansai has jurisdiction over the following 3 subdistricts:

Ansai has jurisdiction over the following 8 towns:

The district, located in the Loess Plateau, is largely hilly, with its elevation ranging from 1,012 metres (3,320 ft) to 1,731.1 metres (5,679 ft) in height. The main rivers of the district are the Yan River, the Xingzi River, the Xichuan River, the Xiaochuan River, the Xiaogou River, and the Shuangyang River.

The district has an average temperature of 8.8 °C (47.8 °F), an average annual rainfall of 505.3 millimetres (19.89 in), and experiences an average of 2,395.6 hours of sunshine per year.

Ansai is a traditionally agricultural district where vegetables, livestock, apples, apricots are produced.^{[citation needed]} Key natural resources in the district include oil, natural gas, iron, limestone, gypsum, kerogen and fire clay.

Ansai's cultural heritage includes typical Shanbei folk art. There is a tradition of paper-cutting, the painting of farmers, clay crafts, waist drums, and folk songs. Ansai's drum music has long been famous. A large number of folk art items are stored in the district office.