Abstract:The speciation of arsenic in edible mushroom was determined by Liquid Chromatography Atomic Fluorescence Spectrometry (LC-AFS) with dilute nitric acid extraction and hydrogen generator,Without UV digestion, Arsenic speciation in edible mushroom was analyzed by gradient elution with Hamilton PRPX-100 as chromatographic column and diammonium hydrogen phosphate as mobile phase. The detection limits of arsenite As (III), methyl arsenate (MMA), dimethyl arsenate (DMA) and arsenate As (V) were 0.2, 0.2, 0.1 and 0.25（ug/L） respectively.The correlation coefficients of the four arsenic species were greater than 0.999 with the linear ranges of 1 μg/L to 100 μg/L. The recoveries of three concentration levels were between 80% and 120%, and the RSD of different concentration levels was less than 5%.The results show that the method has the advantages of simple operation, high sensitivity and good accuracy.It is suitable for the analysis of four arsenic species in edible mushroom, especially the sensitivity of inorganic arsenic determination, and provides strong support for food safety.