An online sample decomposition and detection method for high-throughput determination of Se content in organic samples was established based on oxygen combustion combined with hydride generation atomic fluorescence spectrometry.The sole product of Se in oxygen combustion,SeO2,was quantitatively captured on the walls of the combustion flask in an open system.It was then eluted online and reacted in situ with 10％(V/V)HC1 carrier solution and 2％(m/V)NaBH4 reductant solution within the combustion flask.After optimization,for a maximum sample processing amount of 0.2 g,the sample analysis throughput was 20 sample/h.The detection limit(LOD,3SD)for Se reached 0.012 mg/kg,and the relative standard deviations for parallel determinations(RSDs,n=6)was 1.7％.The analytical results of certified reference materials,scallop(GBW10024)and chicken(GBW10018),were consistent with the certified values,and the analytical results of real samples were in good agreement with those obtained by traditional wet digestion.