The Manas Lake (simplified Chinese: 玛纳斯湖; traditional Chinese: 瑪納斯湖; pinyin: Mǎnàsī hú) is a salt lake in China's Xinjiang Uighur Autonomous Region. It is located in the western part of the Dzungarian Basin, within the Gurbantünggüt Desert. Administratively, the lake is in Hoboksar Mongol Autonomous County; the closest urban settlement is Urho District of Karamay City, some 40 km to the northwest of the lake.
The Manas Lake used to be known as the Yihehake Lake (伊赫哈克湖, Yīhèhākè hú) in the past.
Notionally, Lake Manas is considered the end point of the Manas River, flowing from the Tian Shan mountains. In practice, however, the river bed is usually dry where it reaches the lake (45°41′00″N 85°44′00″E / 45.68333°N 85.73333°E), and little river water reaches the lake.
The Manas Lake area is characterized by arid climate with hot summers; the average annual precipitation of merely 63.7 mm, as compared to the average annual evaporation of 3,110.5 mm; which means that without an inflow of water from outside, the lake's water level can drop very quickly. Over the second half of the 20th century and the early years of the 21st century, it went through the cycle of shrinking, drying up, recovering, or existing as an intermittent lake.