The karst groundwater resource is the key water supply for native residents and industrial and agricultural production in karst regions of southwest China and is even the only water supply for rural regions. Understanding the formation mechanism of hydrochemical compositions is practically imperative to the sustainable development and utilization of karst groundwater resources. The hydrochemical ions of 34 karst spring samples and 12 underground river water samples from the Qingjiang River Basin were measured and analyzed in this study. On the basis of investigating the distribution characteristics of hydrochemical components, methods such as hierarchical clustering analysis, Gibbs model, and relationships between hydrochemical components were used to comprehensively reveal the chemical genesis mechanism of karst groundwater from the perspectives of water-rock interaction and anthropogenic activities, especially in the disturbance mechanism of acidic pollutants on the natural dissolution of carbonate rocks. The results showed that the karst groundwater in the Qingjiang River Basin was weakly alkaline （7.12 ≤pH ≤ 8.69）, and the overall water quality was good. Only the maximum concentration of NO