A high performance aqueous normal phase(ANP) chromatography-tandem mass spectrometric method was established for the simultaneous determination of glyphosate(GLY) and aminomethylphosphonic acid(AMPA) in plant-derived foodstuff.The sample was extracted with ultrapure grade water,and purified with anion-exchange column(MAX).The seperation of GLY and AMPA were carried out by ANP chromatography using 5 mmol/L ammonium acetate(A) and 5% water-95% acetonitrile ammonium acetate solution(B) as mobile phases.The detection of target compounds was performed by MS under electrospray ionization source,negative scanning mode and multiple reaction monitoring.The external standard method was used for the quantitative analysis.The result indicated that the linear ranges of GLY and AMPA were in the concentration ranges of 10-500 μg/L and 20-1 000 μg/L,respectively,with correlation coefficients more than 0.99.The limits of detection(LODs,S/N=3) of two compounds were both 0.01 mg/kg,and the limits of quantitation(LOQs,S/N=10) were 0.02 mg/kg for GLY and 0.04 mg/kg for AMPA,respetively.The recoveries of GLY and AMPA in six matries ranged from 78% to 113%,with relative standard deviations(RSDs) of 3.2-11.0%.The method could meet the requirements for daily food determination with its high sensitivity,recovery and selectivity.