OBJECTIVE：To establish the method for determination of chloramphenicol residue in animal medicinal herbs. METHODS： UPLC-MS method was adopted. The determination was performed on SB-C18 column with mobile phase consisted of acetonitrile-water （gradient elution） at the flow rate of 0.2 mL/min. The column temperature was 35 ℃， and sample size was 20 μL. The ion source was a jet stream ion focusing electrospray ion source. The temperature and flow of drying gas were 350 ℃ and 5 L/min， and those of sheath gas were 250 ℃， 11 L/min ，and capillary voltage was 3 500 V. Negative ion scanning mode was conducted with multiple reaction monitoring （MRM） mode. RESULTS： The linear ranges of thiamphenicol， florfenicol and chloramphenicol were 0.5-15 ng/ mL（r were 0.999 8，0.999 9，0.998 9，respectively）. The limits of quantitation were 0.03，0.03，0.15 μg/kg， and the limits of detection were 0.01，0.01，0.05 μg/kg. RSDs of precision， stability and reproducibility tests were all lower than 3.0％. The recoveries were 84.00％-112.80％（RSD＝10.15％，n＝9），88.24％-109.80％（RSD＝7.11％，n＝9），88.24％-99.02％（RSD＝3.91％，n＝9）。CONCLUSIONS： The method is simple， precise， stable and reproducible， and can be used for determination of chloramphenicol in animal medicinal herbs.