Dongling Lake, located north of the Qarhan Salt Lake, a large potash enrichment zone in the Qaidam basin, exhibits carnallite deposits associated with shallow rock salt layers. Geological exploration indicates the potential for low- grade solid potassium deposits along the lake's shallow periphery. This study investigates the water chemistry, sedimentary features of borehole sediments, and distribution of potassium resources in various brine types (lake surface brines, borehole intercrystalline brines, confined brines) and shallow borehole (0~8 m) salt sediments in Dongling Lake. Additionally, a comparative analysis of potassium deposit distribution in Qarhan Salt Lake is conducted to elucidate the mineralization processes and significance of potassium resources in the study area. Key findings include: ① Intercrystalline brines from the sunken borehole area around Dongling Lake exhibit the highest average K+concentrations (3.19 g/L), followed by confined brines in the sunken borehole (1.46 g/L). Lake surface brines and intercrystalline brines from the lake borehole show relatively lower K+ concentrations of 0.74 g/L and 0.79 g/L, respectively. Salinity (TDS) in Dongling Lake brine samples varies widely, ranging from 80.63 to 547.11 g/L, with no significant positive correlation observed between TDS and K+ concentrations across different brine types. ② Borehole analysis reveals salt- bearing strata with thicknesses ranging from 4.2 to 6.4 m, predominantly composed of stone salt with intermittent carnallite deposits and occasional occurrences of potassium salt. Carnallite exhibits a stratified and rhythmic structure alongside the stone salt. ③ Liquid potassium deposits in Dongling Lake are primarily concentrated in the southwestern region, with K+ concentrations in brines ranging from 4.33 to 6.29 g/L and KCl grades from 0.21% to 0.47%. Solid potassium deposits are predominantly found in the southern part of the lake, exhibiting sedimentary potassium contents ranging from 2.05% to 4.86% and KCl contents between 3.92% and 9.29%. ④ Both the Dongling Lake carnallite sedimentary area and the stratiform carnallite deposits in Qarhan Salt Lake are distributed along the deep fault zone on the northern margin. The latter is mainly found in the mixed zone of chlorine- type water in the north and magnesium sulfate subtype water in the south, specifically within the northern margins of the Dabuxun and Bieletan depressions. Combining Na+, K+, Mg2+, Ca2+//Cl- H2O system phase diagrams with K+- Ca2+ correlation analysis suggests that Ca- Cl water recharge along the deep fault zone south of Dongling Lake facilitated carnallite deposition.