A rapid, sensitive and selective high performance liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was developed and validated for the simultaneous determination of four phenolic acids (neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and ferulic acid) and seven alkaloids (berberine, epiberberine, coptisine, magnoflorine, berberubine, palmatine and jatrorrhizine) in rat plasma. After mixing with the internal standards tetrahydropalmatine (IS1) and rosmarinic acid (IS2), plasma samples were pretreated by protein precipitation using acetonitrile. The HPLC analysis was performed on an Agilent Eclipse plus C18 (4.6mm×100mm, 1.8μm) column with mobile phase consisting of 0.1% formic acid aqueous solution and acetonitrile at a flow rate of 0.3mLmin−1. The detection was accomplished for the analytes and internal standards using positive electrospray ionization for the alkaloids and negative electrospray ionization for the phenolic acids in multiple-reaction monitoring mode. The method showed a good linearity over a wide concentration range (r2>0.99). The lower limit of quantification of seven alkaloids was lower than 2ngmL−1 and that of four phenolic acids was less than 20ngmL−1. The developed method was applied to the pharmacokinetic study of 11 components after oral administration of traditional Chinese medicinal preparation Jinqi Jiangtang Tablet in rats.