Dujiangyan is a county-level city of Sichuan Province, Southwest China, it is under the administration of the prefecture-level city of Chengdu. Its north-west region forms a border with southern Ngawa Tibetan and Qiang Autonomous Prefecture. It has an area of 1,208 km² and had a population of 600,000 in 2003.
Dujiangyan was formerly a county named Guanxian or Guan County. The county became a county-level city in 1988 and was renamed after the Dujiangyan Irrigation System, in the city's northwest, famous for providing Chengdu with water for over two millennia, since around 250 BC.