Abstract: The sample of astragalus was digested with HNO3 and H2O2, and the contents of total selenium, inorganic selenium and organic selenium were determined by HG-AAS. Hydride of Se ion was generated by reacting with 15 g·L-1 KBH4-3 g·L-1 NaOH solution. Flow-rate of 240 mL·min-1 for carrier gas was taken in the analysis. Linear relationship between values of absorbance and mass concentration of Se found was in the range within 60 μg·L-1, with detection limit (3σ) of 0.21 μg·L-1. The proposed method was applied to the determination of Se in astragalus, giving values of 105 μg·g-1 for total Se, 15 μg·g-1 for Se(Ⅳ), 9 μg·g-1 for Se(Ⅵ) and 81 μg·g-1 for organic Se. It was found that the main species of Se in astragalus was organic Se, amounting to 77% of the total Se.