Abstract: This dataset is provided by the 'Detailed prospecting of water supply hydrogeology in Alashan League in Inner Mongolia' from the Geological Survey Institute of Inner Mongolia. It contains data of water pumping tests (12 drilling points), ground water chemical (40 water samples), rock sample tests (102 rock samples) and simultaneous measurement of groundwater level (35 test points). Data of borehole pumping test includes Aquifer lithology, Water depth, Static water level elevation, water level drop depth, gushing water, permeability coefficient, pressure coefficient, Water temperature, mineralization degree, etc. Data of groundwater hydrochemical results include main ion content, Soluble CO₂, Free CO₂, H₂SiO₃, Soluble total solids, total hardness, Total alkalinity, pH, etc. Data of rock and soil samples results include specific yield, permeability coefficient K, particle composition, etc. Data of simultaneous measurement of groundwater level include ground elevation, well depth, wellhead elevation, water level, aquifer, etc. According to the requirements for water resources, the data can provide evidence for developing groundwater resources, ensuring sustainable development of the economy and ecological environment. We take the domestic standards data processing method and principles to ensure observational data quality.