Qaidam Basin, also spelt Tsaidam (Chaidamu Pendi, 柴达木盆地; Mongolian: Цайдам) is an arid basin in Qinghai, western China. Its large natural reserves caused a great deal of investment interest from 2005. Around 35,000 square kilometers, or one third of the basin was desert, which is named after the basin as Chaidamu Pendi Shamo 柴达木盆地沙漠).
It has reserves of asbestos, borax, gypsum, natural gas, and several metals, with the greatest reserves of lithium, magnesium, potassium and sodium of anywhere in China. Qaidam is also home to the Qarhan Lake, which contains sixty billion tons of salt. There are 22 oilfields, with estimated reserves of 225 million tons, and 6 gasfields, holding 150 billion cubic metres of gas.