In order to find out the geochemical and hydrogeochemical background associated with high fluoride groundwater in Gaomi and to study the regularity governing sources, movement, and concentration of fluoride in groundwater, the authors collected 382 pieces of rock and soil samples, 300 pieces of groundwater samples, and analyzed the main components in them. The authors intensively studied the relationships of F^- with geotechnical category, pH of groundwater, Na⁺, Ca²⁺, Cl^-, SO₄^2-, and the horizontal and vertical distribution characteristics of F^-. Some conclusions have been reached: the main sources of fluorine in groundwater in this area are sandstones, conglomerate, mudstones, volcanic rock and pyroclastic rock in the south hill bedrock area; the horizontal distribution of soil fluorine content increases from south to north, and the vertical distribution of soil fluorine content decreases from top to bottom; the fluoride content in the high fluoride groundwater is positively correlated with Na⁺, and negatively correlated with Ca²⁺, and there is no significant correlation between fluoride and anions concentration and no significant correlation between fluoride and total dissolved solid; nevertheless, there exists weak positive correlation between fluoride and the value of pH. The result of the research on the geochemical and hydrogeochemical background in high fluoride areas can serve as a reference for the research on the formation, migration and accumulation of the high fluoride groundwater in the endemic fluorine disease area.