Changji is a county-level city situated about 40 km (25 mi) west of the regional capital, Ürümqi in Northern Xinjiang, China and has about 390,000 inhabitants.

It is the seat of Changji Hui Autonomous Prefecture.

At the northeast corner of the modern city are the walls and other archaeological remains of the Tang dynasty city, usually referred to as Ancient Changji.

In the area around Changji crop growing, animal husbandry and oil crop growing are important parts of the economy.

Changji is served by China National Highway 312, the Northern Xinjiang and the Second Ürümqi-Jinghe Railways.