Aiming to identify impact factors of unbalances of water supplies and water demand (referred to WSD) of Yellow River Basin under extreme dry years to support water resources management, the WSD was measured by ranges and depth of WSD. Besides, responses of WSD on metro-hydrological elements, economic and society, reservoir regulation, ecology and environments were explored by the principal component analysis method (PCA). Moreover, uncertainties of surface water supplies and discharges of reservoirs were measured by stochastic functions that were verified by Kolmogorov-Smirnov test (K-S) and augmented dickey fuller (A-D) approaches. The influences of single and interactive parameters on WSD were studied by three-level factors method. The results showed that WSD of Yellow River Basin ranged from medium, relatively high and high degree. Surface water supplies and discharges of reservoirs had the most impacts on WSD and explanation rate reached about 55.055%. Xiaolangdi reservoir had the biggest impact on WSD, followed by surface water supplies and Wanjiazhai reservoir. These results could identify key impact factors of WSD under interactions among hydrometeorology, socioeconomics, reservoir operation and ecol ogical environment. Besides, it could explore impacts of uncertainties on WSD, supporting water resources management of Huanghe River.