<p>The Zonag Lake basin is situated in the hinterlands of the Qinghai-Xizang Plateau (QXP) and serves as a renowned calving ground for Tibetan antelopes. Zonag Lake is also a typical large inland lake on the QXP. Over the past three decades, the lake areas within the Zonag Lake basin have generally shown an expanding trend. However, different lakes therein have exhibited varying trend over time. Between 1988 and 1995, Zonag Lake, Kusai Lake, Haidingnor Lake, and Salt Lake all experienced shrinkage. After the 2011 breach of Zonag Lake, it continued to shrink, the downstream lakes, such as Kusai Lake, Haidingnor Lake, and Salt Lake consistently expanded. After the 2019 implementation of the Salt Lake drainage project, the water levels began to decline in 2020. The Zonag Lake basin has experienced an average annual precipitation of 308.5 mm over the past six decades, with a general upward trend in rainfall amounting to an average increase rate of 15.1%. The overall temperature within the basin has also been increasing, with a warming rate of 0.35 °C/10 a. This trend has become notably more pronounced since the beginning of the 21^st century. Collectively, surface runoff (41.5%±2.3%) and lake precipitation (27.0%±1.5%) accounted for most of the total lake inflow, thus identifying atmospheric precipitation as the primary driver of lake expansion in the Zonag Lake basin. The meltwater from glaciers and permafrost was the secondary contributor, responsible for 24.0%±1.3% of the inflow.</p>