To establish a LC-MS/MS method for simultaneous determination of Basic Orange 2 and Basic flavine 0 in soy product.The samples were extracted with ethanol and cleaned up by Oasis HLB solid phase extraction column,0.1% water formic acid-0.1% methanol formic acid was used as mobile phase.Basic Orange 2 and Basic flavine O were determined by LC-MS/MS.There was a good linear relationship at the range of 0~500 ng/mL of Basic Orange 2 and Basic flavine O with r>0.995,the limitation of detection of Basic Orange 2 and Basic flavine O were 0.5 μg/kg and 0.8 μg/kg,respectively.The rate of recovery was from 87.2% to 94.5% and the relative standard deviations were from 1.65 to 4.08%.The method is rapid,accurate and suitable for simultaneous determination of Basic Orange 2 and Basic flavine O in soy product.