Abstract：To find out the distribution and formation conditions of high-fluorine groundwater in Dali County, Shaanxi Province, the authors made a systematic analysis from several angles, such as strata, weather, terrain and landform, hydrogeology and hydrochemistry. The results show that the high-fluorine groundwater is jointly controlled by terrain, landform and hydrogeology. Meteoric water brings fluorine element in rock and soil into groundwater through water-rock reaction during its infiltration and leaching, and such water is concentrated during the evaporation to form high-fluorine water. This research provides hydrogeological grounds for solving the problem of safe water drinking in Deli County.