Abstract:The selenium in infusions of black tea，oolong tea and green tea was determined by microwave digestion-atomic fluorescence spectrometry to find a correct way for drinking selenium-rich tea.Meanwhile，the law of the rate of selenium dissolution in tea infused in boiling water changing with the time was investigated at（25± 2）℃.The result showed that the accuracy，precision，limit of detection and linear range and correlation of standard curve of the determination of selenium in tea infusions were in accordance with the requirements of quantitative analysis methodology.The content of the selenium in black tea，oolong tea and green tea infusions was 104.27，149.48 μg/kg and 179.93 μg/kg，respectively.When the tea/water ratio was 1 ∶200（g/mL），selenium dissolution in black tea，oolong tea and green tea brewed in boiling water at（25±2）℃peaked at 20，60 min and 120 min，and dissolution rate was 68.31%，65.44% and 67.51%，respectively.The water temperature decreased regularly and the selenium concentration in tea infusions reduced at different rates over time.After 5 h，the selenium concentration in black tea，oolong tea，and green tea infusions decreased to 10.09，10.35 μg/kg and 83.31 μg/kg，respectively.