A new method was developed for the speciation of inorganic arsenic in coal samples by liquid chromatography coupled to hydride generation atomic fluorescence spectrometry after microwave-assisted extraction. Effective extract of As(III), As(V) in coal sample was achieved by 1.0molL-1 H3PO4 and 0.1 molL-1ascorbic acid. Under the optimized conditions, the limits of detection were 0.01 ugL-1and 0.02 ugL-1for As(III), As(V). The relative standard deviation were 2.4 %, 3.3 % (c= 20.0 gL-1, n=7). The proposed method was successfully applied for the determination of speciation of inorganic arsenic in coal samples and GBW11117.