Abstract: Objective:To establish a direct determination method of taurine in infant milk powder by hydrophilic interaction chromatography-mass spectrometry(HILIC-MS/MS). Method:After extraction,acetonitrile and 10 mmol/L ammonium formate(0.05% formic acid)were used as the mobile phase for gradient elution,mass spectrometry was used for quantitative determination of taurine in the negative ion mode by multiple reaction monitoring(MRM). Results:The linear relationship was good in the range of 10~200 ng/mL,and the correlation coefficient was 0.9997,the detection limit was 0.04 mg/kg,the recoveries were 81.2%~90.5%,and the relative standard deviations were less than 4.0%. Conclusion:The method was rapid,accurate and sensitive,and could be applied to the direct determination of taurine in infant milk powder.