Objective To establish the method for content determination of three lignans of Dendrobium Fimbriatum Hook..Methods The lignans in Dendrobium tasselii were identified by high-performance liquid chromatography/multi-stage mass spectrometry(HPLC-ESI/MSn)coupled with ultraviolet absorption spectrometry(UV)coupled with retention time localization of high-performance liquid chromatography(HPLC).The separation was carried out on a Kromasil 100-5 C18 column(4.6 mm×250 mm,5 μm)using a gradient elution of acetonitrile-0.1%formic acid solution as the mobile phase,the volume flow rate was 0.8 mL·min-1 and the column temperature was 35℃,and the mass spectrometry was performed using an ESI ion source with the data collected in the negative ion mode.The HPLC content was determined on the same column as that of MS analysis,with the mobile phase methanol + acetonitrile(V/V=1∶1)-0.01 mol/L ammonium acetate solution,gradient elution,flow rate of 0.8 mL·min-1,column temperature of 40℃,and detection wavelength of 215 nm.Results Syringaresinol di-O-glucoside and(-)-Syringaresinol 4-O-β-D-glucopyranoside and DL-Syringaresinol were identified from Dendrobium fimbriatum Hook.,and the results of content determination showed that the linear ranges of above three components were respectively 0.1701-3.4020,0.1020-2.0400,0.0403-0.8060 μg(r≥0.9995),the average recoveries were in the range of 97.71%-101.67%,and the relative standard deviations(RSDs)were all less than 3.0%.The contents of Syringaresinol di-O-glucoside and(-)-Syringaresinol 4-O-β-D-glucopyranoside and DL-Syringaresinol in the 10 batches of samples were 0.7779-1.3852,0.0734-0.1966,0.0295-0.1882 mg·g-1.Conclusion This research method can provide a reference basis for the quality evaluation method of Dendrobium fimbriatum Hook..