Zhang County or Zhangxian is an administrative district in Gansu, the People's Republic of China. It is one of 58 counties of Gansu. It is part of the Dingxi prefecture, with the city of the same name being the prefecture seat. Its postal code is 748300, and its population in 1999 was 186,100 people.
Coordinates: 34°43′N 104°22′E / 34.717°N 104.367°E