The hydro-chemical characteristics and distribution of groundwater with high fluorine in Longyao are revealed according to the date from chemical analysis of the groundwater,and the formation of the groundwater is discussed through the condition of stratum,physiognomy,and hydro-geochemistry,weather.The condition of stratum is the foundation,and physiognomy,and hydro-geochemistry,weather are the main influencing factors to decide the background contain of the formation of the groundwater in Longyao.Moreover the formula distinguished high,low fluorine groundwater has established and that can be consulted to seek,exploit low fluorine groundwater resource in this region.