UPLC-MS-MS system was used for the identification of arbidol metabolites in the rat feces, urine and plasma samples. The system was so powerful a way with high ability of separation and analysis, based on both chromatography and mass properties. The isotope of Br was also a good indicator for metabolites finding. There were altogether 9 metabolites detected and identified, including 2 phase I biotransformation products and 7 phase II ones. It is concluded that arbidol mainly undergo metabolic reactions such as N-demethylation, S-oxidation, glucuronidation and sulfation in rats.