|Abstract:This article took the essential elemental fluorine as the research object, and selected the entire area of Shandong Province, which had typical endemic fluorine disease distribution and comprehensive groundwater type distribution, as the research area. Based on 4,321 pieces of groundwater inorganic analysis data collected from 2006 to 2016, the distribution characteristics and driving mechanisms of fluorine enrichment in groundwater in Shandong Province were studied in detail, using mathematical statistical analysis, ion ratio analysis, and water chemical equilibrium system analysis methods. The results show that: the distribution of shallow high fluoride groundwater was contiguously distributed in the low-lying areas of the Jiaolai Basin and the Southwestern Plain of Shandong. The distribution area where shallow groundwater fluorine concentration exceeding 1mg / L is about 13227km2, with a fluorine concentration maximum of 22mg/L. The distribution of deep pore groundwater with high fluoride is concentrated in the deep groundwater depression funnel areas of Dezhou, Binzhou and Heze. The distribution area where deep pore groundwater fluorine concentration exceeding 2mg / L is about 15086 km2, with a fluorine concentration maximum of 7.5 mg/L. Groundwater extraction is the main factor driving fluorine enrichment in deep pore water. The average concentration of fluorine of different types of groundwater in descending order is deep pore water, shallow pore water, bedrock fissure water, fissured karst water, and pore fissure water. The fluoride concentration of deep pore water has a significant negative correlation with Ca2+ concentration, and the correlation is not obvious in other types of groundwater. It is concluded that the formation of high fluoride groundwater in Shandong Province is driven by three factors, including geomorphology and geological structural parts, the geochemical characteristics of the aquifer medium, and human groundwater extraction. Leaching, evaporation and water-rock interactions further increase the groundwater fluorine content, and the fluorine-calcium antagonistic mechanism ultimately determines the fluorine content in groundwater. This study revealed the key factors controlling the fluorine enrichment of different types of groundwater and deepened the understanding of the chemical behavior of fluorine in groundwater.