Objective To establish a method for determination alpha-solanine in potatoes by liquid chromatography-tamdem quadrupole mass spectrometry. Methods The potato samples were extracted using the mixed solution of acidity water and organic solvent by accelerated solvent extraction. After the purification by MCX solid phase extraction, the eluent was dried-up with nitrogen. The analytes were dissolved by the mobile phase(acetonitrile-water containing 0.1% formic acid,80∶20,V/V)and separated by hydrophilic interaction chromatography(2.1 mm×50 mm,1.6 μm) and determined using multi-reaction monitoring mode. The conditions of the pretreatment solution, liquid chromatography and matrix effect were optimized. Results The limits of detection and quantification were 0.5 and 1.6 μg/kg. The linear range of standard curve were from 0.1 to 100 μg/L. The relative standard deviations of detection were at 3.41%-7.56%(n=6), and the spiked sample recoveries were at 82.8%-99.0%. Conclusion The simplicity, efficiency, sensitivity and accuracy of this method can meet the needs of risk monitoring and poisoning analysis.