An ultra performance liquid chromatography tandem mass spectrometric(UPLC-MS/MS)method was successfully developed for the simultaneous determination of ribavirin and its metabolites 1H-1,2,4-triazole-3-carboxamide(TCONH2) and 1-β-D-ribofuranosyl-1,2,4-triazole-3-carboxylic acid(RTCOOH).13C5-labelled ribavirin was used as an internal standard in this approach.After precipitation of proteins in chicken plasma by adding methanol,the pretreated sample was separated on a ZORBAX SB-Aq column(100 mm×3 mm,18 μm) by a gradient elution program using 0.1% formic acid water solution and methanol as mobile phase.The target analytes were detected by electrospray ionization-mass spectrometry under positive MRM mode.The result indicated that the calibration curves were linear in the ranges of 5- 5 000 μg/L for ribavirin and TCONH2,and 50-5 000 μg/L for RTCOOH,with correlation coefficients of 0.994 7,0.999 2,0.997 6,respectively.The average recoveries of ribavirin,TCONH2 and RTCOOH were in the range of 84.1%-108.2% with intra-assay relative standard deviations(RSDs,n=6) of 1.6%-13.4% and inter-assay RSDs(n=12) of 3.8%-16.9% .The limits of detection(LOD) for ribavirin,TCONH2 and RTCOOH in chicken plasma were 2 μg/L,2 μg/L and 10 μg/L,respectively.With merits of rapid analysis,good repeatability and wide linearity range,the method could be a powerful tool for the study of ribavirin pharmacokinetics and metabolism in chicken plasma.