Potassium salts are a strategic mineral resource for China, and Tibet's salt lake brines hold abundant reserves, necessitating thorough investigation and evaluation of their potassium content. This study constructs a multi- temporal dataset of potassium concentrations in Tibetan salt lake brines, analyzes their spatiotemporal distribution characteristics, and investigates the factors influencing these patterns. Our research reveals the following: ① Potassium concentrations in Tibetan salt lake brines increased from 1980 to 2000, primarily due to a reduction in glacial meltwater supply. Conversely, from 2000 to 2020, potassium concentrations decreased, with increased rainfall being the main factor. ② Potassium concentrations display significant spatial heterogeneity across the Tibetan salt lake brines. High concentrations are concentrated in the region between east longitudes 82° and 85° and north latitudes 31.5° and 34°. A distinct spatial pattern emerges, characterized by higher concentrations in the western and southern regions, and lower concentrations in the eastern and northern regions. This heterogeneity is primarily attributed to variations in lithology, regional climate, and the characteristics of upstream catchments. ③ Potassium concentrations vary systematically among different hydrochemical subtypes of brines, following the order: sodium sulfate subtype>chloride subtype>magnesium sulfate subtype>carbonate subtype. This study provides important baseline data for understanding the variability of potassium content in Tibetan salt lake brines and for evaluating the potential of potassium salt resources in the region.