Abstract：Endemic fluorosis related to domestic coal combustion is widely spread around Guizhou Province, but its source is still unclear. Analysis of samples of waters, coals and soils collected from Zhijin, Nayong and Pingba Counties where the disease is common reveals that the source of fluoride comes mainly from coals in areas where low quality coals or coals with high fluorine are exploited, and is derived from soils in other areas. Merely drinking water seems not likely to cause endemic fluorosis. It is therefore suggested that stopping the mining of low quality coal or coals with high fluorine and making use of near-surface soil could possibly relieve the damage of fluoride in the province.