Abstract: The five fluorine species including water soluble fluorine, ion exchangeable fluorine, reducible fluorine, oxidizable fluorine and residual fluorine, in fluorinerich soils in Yanchi County, Ningxia municipality were studied by sequential extraction and ion chromatographic analysis. The extraction reagents and conditions used in the sequential extraction were discussed. The detection limit of the method for F- by ion chromatography is 0.76 μg/g with the precision (n＝7) of 11.3%RSD for water soluble fluorine, 13.5%RSD for ion exchangeable fluorine, 10.7%RSD for reducible fluorine and 8.9%RSD for oxidizable fluorine.