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The antimony (Sb) content of shallow drinkable groundwater at Xikuangshang mine area (in Hunan province, China) has exceeded China's national drinking water quality guidelines, posing a serious threat to the health of residents in the mine area. The difference in hydrogeochemistry characteristics and water-rock interactions between low Sb groundwater (<0.015 mg/L) and high Sb groundwater (>0.015 mg/L), however, remains unclear. In this study, 24 samples were collected from shallow drinkable groundwater at the mine area. The hydrogeochemistry data and water-rock interactions were analyzed to reveal the condition leading to the formation of high Sb groundwater. Compared with low Sb groundwater, high Sb groundwater has a higher level of Na+, TDS, and SO 4 2-, which increase by 6.38, 1.84, and 4.04 times, respectively. The low Sb groundwater is mainly controlled by Ca–HCO 3 –SO 4 type, whereas the high Sb groundwater is controlled by Ca–HCO 3 –SO 4 type as the main facies, and Ca–Na–SO 4 type and Ca–SO 4 –HCO 3 type as the secondary facies. The chemical composition of low Sb groundwater is mainly influenced by the dissolution of carbonate minerals and the chemical composition of high Sb groundwater is controlled by ion-exchange interaction and dissolution of carbonate minerals and silicate minerals, among which ion-exchange interaction is the most important factor. The outcomes of this research provide a better understanding of the mechanisms of Sb pollution in groundwater and it will help in securing safe drinking water sources for local communities. • Geochemistry characteristics are analyzed between low and high Sb groundwater. • Ion-exchange interaction is the most important factor for high Sb groundwater. • Part of high Sb groundwater have reached water-silicate equilibrium. • The mechanisms of Sb pollution in shallow groundwater of Xikuangshang mine area. [ABSTRACT FROM AUTHOR]