A relatively simple and fast phosphorescence method for the detection of baicalein（BAI） was established,based on that baicalein could quench the room temperature phosphorescence（RTP） of PEI-Mn/ZnS quantum dots（QDs） prepared by water phase coprecipitation through electron transfer effect.The experimental results showed that,at pH 80 and a reaction time of 10 min,the phosphorescence quenching degree of QDs had a linear relationship（r=0997） with BAI in the concentration range of 007-060 mg·L-1.The detection limits of the method were 0039 mg·L-1,and the relative standard deviations were 41%.The spiked recoveries for practical samples were in the range of 960%-1007%.The established method,effectively avoiding the interference of common ions and amino acids etc., could be used for the rapid determination of BAI in scutellaria baicalensis georgi and serum,which is expected to be applied in the determination and analysis of BAI in medicine industry.It also provides a technical basis for the detection of other drugs based on the mechanism of QDs electron transfer.