Abstract: A method for the determination of 5 organic explosives, including of trinitrotoluene (TNT), 2,4,6-trinitrobenzylamine (CE), pentaerythritol tetranitrate (PETN), cyclotetramethylene tranitramine (HMX), cyclotrimethylene trinitramine (RDX), in explosion dust by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was proposed. 10 g of explosive dust was added into 20 mL of acetone. After mixing well and centrifugation, the supernatant was blew to dry with nitrogen. Then 1 mL of methanol was added, and the above solution was dissolved by ultrasound and filtered with 0.22 μm organic filter membrane. A mixture of 0.5 mmol·L^-1 ammonium acetate solution and methanol at different volume ratios was used as mobile phase for gradient elution. ESI^- mode and MRM mode were used for MS analysis. As shown by the results, linear relationships between values of mass fraction of 5 organic explosives and their peak areas were kept in definite ranges, with detection limits (3S/N) in the range of 0.033-0.05 μg·kg^-1. Test for recovery was made on the blank dust sample at 3 concentration levels by standard addition method, giving results in the range of 61.6%-99.0%, and intra-day precision (n=5) and inter-day precision (n=5) were in the ranges of 1.1%-7.1% and 4.2%-9.8%. This method has been applied to the analysis of actual samples, giving detection amount of 67.7 μg·kg^-1 for TNT, and the other 4 organic explosives were not detected.