Abstract: In order to reveal the characteristics and the main driving factors of hydrologic regime evolution in the Ganjiang River Basin, based on the measured discharge and water level data from 1953 to 2020 at the Waizhou Station of the Ganjiang River Basin, moving average method, Kendall rank correlation test, Spearman rank correlation test, cumulative departure test, Mann-Kendall test, moving rank sum test, Pettitt test and ordered cluster test were used to analyze the variation characteristics of discharge and water level at the station.Random forest model and residual analysis method were used to quantitatively evaluate the effects of human activities and climate change on the changes of discharge and water level.The results showed that:(1) the annual and monthly average discharge showed an insignificant increasing trend, the annual average discharge increased by 10.5% with a rate of 3.2(m3·s-1)/a; the annual and monthly average water level showed a significant decreasing trend, the annual average water level decreased by 14.3% with a rate of-0.04 m/a;(2) 1991 was the abrupt change year for the annual average discharge series at the Waizhou Station, and the discharge increased by 205 m3/s in impact period compared to that in the baseline period.The contribution of climate change and human activities to the discharge change was quantitatively analyzed, climate change accounting for 92.8%,and the increase of precipitation in the Ganjiang River Basin was the main reason for the slight increase in discharge at the Waizhou Station.(3) 2002 was the abrupt change year for the annual average water level series at the Waizhou Station, and the water level decreased by 2.20 m in the impact period compared to that in baseline period, and the contribution of human activities to the water level change accounted for 93.8%.Due to the impacts of water conservancy projects construction, comprehensive basin treatment and other human activities, the natural flow and sand rules of the river has been changed.The cross section of the Waizhou Station was affected by scouring and siltation changes and artificial sand mining, leading to a significant riverbed scouring from year to year.What mentioned above were the main reasons for the significant decrease of the water level at the Waizhou Station.The research results can provide a reference for water resources utilization in the basin under changing environment.