Ngari Prefecture or Ali Prefecture is a prefecture of China's Tibet Autonomous Region covering Western Tibet, whose traditional name is Ngari Khorsum. Its administrative centre and largest settlement is the town of Shiquanhe. It is one of the least densely populated areas in the world, with 0.3 people per kilometer.

Gar County, formerly Senge Tsangpo County, is a district (county) in the Ngari Prefecture of the western Tibet Autonomous Region of China. The main town is Shiquanhe (Sênggêkanbab), also called "Gar", on account of being the county seat, and "Ali", on account of being the seat of Ngari Prefecture.