An ultra high performance liquid chromatography coupled with linear ion trap-orbitrap mass spectrometric(UPLC-LTQ-Orbitrap-MS) method was developed for the qualitative analysis of main chemical constituents in Duzhong granules,a Chinese medicine.The sample was ultrasonically extracted with methanol,then separated on a Thermo Scientific Syncronis C18 chromatographic column(100 mm×21 mm,19 μm) by gradient elution with acetonitrile-01% formic acid as mobile phase.The data were collected by using LTQ-Orbitrap-MS in negative ion mode.According to the contrast of the reference standards and the accurate masses of molecules,a total of 25 compounds in Duzhong granules were identified,including 8 iridoids,8 flavonoids,5 phenylpropanoids,3 lignans and 1 non reducing disaccharide.Results showed that,with the advantages of simplicity,rapidness and accuracy,the developed method was suitable for the identification of chemical constituents in Duzhong granules,which provided a reference for the pharmacological basis of further analysis of Duzhong granules.