Abstract: A method for determination of selenium in food by hydride generation-atomic fluorescence spectroscopy (HG-AFS) using semi-fusion separation with aiskaer reagent. Aiskaer reagent (a mixture of magnesium oxide and sodium carbonate at mass ratio of 3:1) of 0.50 g and sample of 0.50 g were mixed well in a quartz crucible and covered with aiskaer reagent of 1.25 g to calcinate at 750℃ for 60 min. 1 drop of 0.1% (mass fraction) phenol red indicator was added, and the color of the solution was changed from red to yellow with hydrochloric acid. The solution was heated to about 6 mL at 200℃, and hydrochloric acid of 6 mL was added to boil for 10 min. Ferric salt solution of 2 mL was added after cooling, and the solution was made its volume up to 25 mL by water. Selenium content in food was determined by HG-AFS. As shown by the results, linear relationship between mass concentration of selenium and its response value was kept within 16.0 μg·L^-1, with detection limit (3s) of 6.0 ng·g^-1. 3 national reference materials (rice, laver and garlic powder) were determined, and RSDs (n=12) of the determined values were in the range of 3.4%-5.2%. This method has been applied for analysis of 16 national reference materials, and the relative errors between the measured values and the certified values were ranged from -10% to 17%.