Yajiang County, also known as Nyagqu, is located in the traditional Kham Region of eastern Tibet. It is situated in the western part of Sichuan Province, China, and falls under the administration of the Garzê Tibetan Autonomous Prefecture.
The name Yajiang is derived from Nyagchukha in the Tibetan language. The county serves as a primary administrative division within its prefecture, characterized by its location in the high-altitude terrain of the eastern Tibetan plateau.