Abstract: Objective to establish a method for the determination of 5-hydroxy tryptamine（5-HT), adrenalin （AD) and noradrenalin （NA) in human plasma using pre-column derivatization HPLC-MS/MS. Methods Derivatives of the plasma samples were produced with dansyl chloride under pH 10.5, and then extracted and enriched with ethyl acetate. The detected chemicals were separated using Ultimate C18 (50 mm×4.6 mm, 5 μm) with acetonitrile-water-formic acid=95∶5∶0.05 （V∶V∶V） at 0.2 mL/min. The HPLC-MS//MS system was operated under a multiple reaction monitoring mode (MRM) using the electrospray ionization technique in positive mode. ResultsLinear range of the calibration curve appeared in 250-2.5 ng/mL. The method had a less than 9% intra- and inter-assay relative standard deviation (RSD), 95.44%-109.71% recoveries, and 4.86%-12.81% matrix effects. ConclusionThis method is simple, accurate, and suitable for detection of 5-HT, AD and NA in human plasma.