Tuanjie Lake is a lake in the southeastern Qarhan Playa north of Golmud in the Haixi Prefecture of Qinghai Province in northwestern China.

Like the other lakes of the surrounding Qaidam Basin, it is extremely saline.

Tuanjie Lake at the southern edge of the Qaidam subbasin[1] in the eastern Qarhan Playa at an elevation of 2,675 m (8,776 ft) above sea level.

[4] Tuanjie's position at the south end of the playa means that its waters are relatively less influenced by the concentrated mineral springs along the playa's northern boundary.

[5] Nonetheless, the lake's brine is at or near saturation with calcite, halite, polyhalite, kieserite, and (importantly) carnallite,[6] which is processed to produce potash for potassium-rich fertilizers and other uses.