Sterigmatocystin,a mycotoxin produced by fungi and widely distributed in cereal food,has a potential toxic effect to human and animals with risk on food safety.In this study,a rapid,simple and accurate high performance liquid chromatography-tandem mass spectrometric(HPLC-MS/MS) method was established for the analysis of sterigmatocystin in rice and millet by optimizing extraction solvent and its volume,ultrasonic time and adsorbent.The samples were extracted with acetonitrile,and cleaned up with PSA,then detected after the supernatant was filtered through nylon filter.The detection was performed in the electrospray ion(ESI) positive mode and multiple reaction monitoring(MRM) mode.The sterigmatocystin showed good linear relationships in the range of 0.1-100.0 μg/L with correlation coefficients not less than 0.999 0．The limit of detection(LOD) and the limit of quantitation(LOQ)for sterigmatocystin in rice were 0.03 μg/kg and 0.1 μg/kg,respectirely,the recoveries ranged from 88.3% to 91.5% with relative standard deviations(RSDs) of 2.3%-6.0%.The LOD and LOQ for sterigmatocystin in millet were 0.1 μg/kg and 0.3 μg/kg,respectively,and the recoveries were 92.7%-103.8% with RSDs of 2.2%-6.9%.The proposed method could meet the requirement for trace analysis.The method was applied in the the detection of the collected rice and millet samples,and no sterigmatocystin was detected.