Abstract: Soil heavy metals are directly related to soil environmental safety and ecosystem stability, and their concealment and long-term persistence pose potential threat to human health． This study was conducted in the Lhasa River Basin on the Tibetan Plateau, providing the first comprehensive assessment at the watershed scale on the concentration levels, spatial distribution characteristics, and potential ecological risks of heavy metals in soils． The results revealed that the average concentrations of Cu, Zn, Cr, Ni, Pb, Cd, and As were below the risk screening values of the national soil environmental quality standards, although a small proportion of samples exceeded these thresholds, with exceedance rates below 16%． A comprehensive assessment of soil heavy metals in the basin was conducted using analytical methods such as the single-factor index, Nemerow comprehensive pollution index, geo-accumulation index, and potential ecological risk index． The results indicate that the overall risk of soil heavy metal is relatively low, only Cd, Cu, and Pb in few samples exhibit moderate or higher pollution risks, with proportions of 29.7%, 6.3%, and 4.7%, respectively． The geo-accumulation levels of Zn, Cr, Ni, Pb, and As were predominantly clean to marginally clean, whereas Cd and Cu showed moderate or higher accumulation in some samples (20.4% and 4.7%, respectively)． The comprehensive potential ecological risk of soil heavy metals is low, except Cd presenting a moderate risk． Future soil management in the basin should prioritize addressing the risk of point-source pollution from Cu, Pb, and Cd in the middle and lower reaches．