Mebendazole （MBZ） was administered to blunt snout breams （Megalobrama amblycephala） by oral gavage，and water samples were collected at corresponding time points of 0.25，0.5，1，2，3，4，5，6，7 and 8 d after drug administration to study the distribution and excretion of MBZ in the body of blunt snout bream.The liquid chromatography-mass spectrometry （LC-MS/MS） was used to determine the concentrations of MBZ and its metabolites in the water samples after extracted and purified by solid-phase extraction.The fish experimented were killed and its blood，liver，kidney，gill，muscle and other tissues were collected and weighed after the water samples were collected on the 8th day.QuEChERS method was used for extraction and purification，LC-MS/MS was used to detect the concentrations of MBZ and its metabolites in each tissue.The recovery amount in each tissue was calculated.Results showed that the recovery amount of MBZ and its metabolites in the heart，liver，spleen，gill，kidney，intestine etc.was ranged from 3 332.26 to 5 345.52 μg accounting for 13.74%-23.74% of the total dose，with the highest recovery amount in the intestine up to 5.18%-12.85% of the total dose.The recovered amount in other tissues was ranged from 987.22 to 1 907.19 μg accounting for 5.19%-11.40% of the total dose.The recovery amount in water was ranged from 1 561.95 to 4 623.15 μg accounting for 6.44%-21.88% of the total dose.The total recovery amount of MBZ was ranged from 6 295.50 to 10 983.41 μg，with the average recovery ratio of 42.64%.It is indicated that MBZ mainly exists in the form of mebendazole，hydroxybendazole and aminobendazole in the body of blunt snout breams，and no other metabolites were detected after oral gavage.MBZ and its metabolites were mainly distributed in the intestine，liver，other tissues，but the overall recovery ratio was low.It is indicated that mebendazole is poorly absorbed in the body of blunt snout breams，and its metabolic pathway is similar to other animals.Mebendazole is mainly excreted through feces and urine.