Abstract: Fluorine is distributed in natural water regularly,by way of zonal or nonzonal distribution.The zonal distribution of fluorine is closely related with weather,topography,landforms,the acid and alkali nature of soils and the temperature of natural water.The nonzonal distribution is mainly related with warm springs,underground hot water,vocannos and the regions associated with deposit containing fluorine. In nature,the rocks containing fluorine are dissolved in water by water disivation.The fluorine contents in natural water is quite different.Under humid climatic conditions,underground water contains a small amount of fluorine.In saline alkli regions under dry climatic conditions,shallow ground water contains a large amount of fluorine.The water in rivers contains a small amount of fluorine.The fluorine contents in lakes are quite different. The fluorine content in sea water is stable.Warm springs and underground hot water contain a large amount of fluorine,so they can not be drunk. The amount of fluorine in natural water is proportional to Na⁺¹,Cl^-1, SO₄^-2 and mineralized degree.Even in a same place,ground water contains a small amount of fluorine in water-bearing strata with coarse particles,and a large amount in strata with fine particles.In saline alkali regions,the water in deep wells contains a small amount of fluorine.Sometimes the water containing a small amount of fluorine can be found on certain sections of river banks.This kind of water can be used as sources water.This paper points out the way to look for the water containing a small amount of fluorine.