O b jective To deve lop an ana lytical me thod for the ana lysis of ac id orange ò in aba lone soup w ith high performance liqu id chromatography2tandem mass spectrome try (H PLC2MS/MS) . M ethod Samples were extracted by methanol+ ammon ium aceta te buffer ( 1+ 1, v/v) and pur ified on an OASISWAX SPE column. The ch roma tograph ic column ofHPLC2MS/MS wasWaters Acuity BEH C₁₈ ( 21 1 mm @50 mm, 11 7 Lm ). Ac id orange ò was de tected by mon itor ing the ion transition ofm /z 32619y 17018 and 3261 9y 1551 8 usingmultiple reactionmonitoring (MRM ) mode. R esu lts The lim it of quantifica tion ( LOQ) was 01 1mg/kg, and the recoveries of two sp iked samples ( 5mg/kg and 50 mg/kg) we re 871 0% and 101% respectively. The calibration cu rves showed good linea rity in the range of 1025000 L g/L w ith correlation coeffic ients larger than 01999. The detection of ac id orange ò in 14 samples from restaurants showed that the concentration of acid orange ò in 7 samp les were 1122731 8 mg/g. Conc lu sion The method cou ld meet the requ irement for fast and accurate detection of acid orange ò in abalone soup.