<p>Qaidam Basin, located in the northeastern Qinghai-Xizang Plateau with high-mountain and deep-valley tectonic setting, is rich in mineral resources of many critical elements of mainly potassium (K), lithium (Li), magnesium (Mg), sodium (Na), uranium (U), and boron (B) leading the nation in these categories. To clarify the distribution and enrichment of potassium and lithium in Qaidam Basin brine, hydrochemical analyses and phase diagrams were carried out on brine water, salt spring water, and inflow river water. Results reveal that paleo-lake water migrated from the northwest to the Triple-lake region in an inverted S-shaped pattern under the control of gravitation. Due to the chemical differentiation, K shows an enrichment trend along the migration path from the northwest to the Triple-lake region, whereas Li is predominantly concentrated in East Taijinar (Dongtai), West Taijinar (Xitai) Lake, and Bieletan mining section in the lower catchments of Nalingele River. The Cl-SO₄ type of brines are widely distributed along the migration pathway. However, river water influx has shifted the hydrochemical type of Dongtai and Xitai lakes and Bieletan section into Na-HCO₃-SO₄ type. Salt spring that distributed along faults contribute a large amount of Ca, K, and Mg elements, thus turn water into Ca-Cl type. Glacial meltwater, after leaching granite and other rock, serves as the primary source of K, and Ca-Cl-typed salt springs are the significant source of both K and Li. These springs have modified the brine chemistry compositions and increased K and Li concentrations in Mahai Lake, Qarhan Salt Lake, and Dalangtan Salt Lake. This systematic analysis of K and Li distribution and enrichment mechanisms provides critical insights for the sustainable exploitation of brine resources in the Qaidam Basin.</p>