Abstract: OBJECTIVE To establish a method for the determination of aflatoxin(AF) in Corydalis Rhizoma by UPLC-MS/MS. METHODS Agilent Zorbax Eclipse C₁₈(2.1 mm×50 mm, 1.8 μm) column was used for separation. Detection was carried out by positive electrospray ionization(ESI) mass spectrometer in multiple reaction monitor(MRM) mode. RESULTS Twenty samples were extracted with 70% methanol solution and AFB1, AFB2, AFG1 and AFG2 were detected. All the 4 kinds of aflatoxin compounds showed good linearity in their reasonable ranges, r ≥ 0.997. The average recoveries of all the compounds were in range of 78.3%-93.7%, the RSD were 1.5%-2.7%(n=6). CONCLUSION The method is specific, sensitive and reproducible which is suitable for the detection of AF in Corydalis Rhizoma. In view of the risk of AF which exists in the market of Corydalis Rhizoma, suggested the addition of the quality examination method in Chinese Pharmacopoeia.