The effects of sample pretreatment on the detection of Mei-ting in the muscle of grass carp was explored by high performance liquid chromatography.The results showed that the pretreatment methods of extraction by methanol,purification by methylene chloride,vibratory centrifugation,defatting by n-hexane,concentration at 30℃ by rotary evaporator,is rapid,sensitive,economical,safe and practical.The detection limit of Mei-ting was 1.0 μg/kg.The recovery rate ranged from 67.72％ to 95.52％ at the spiking level of 1.0-100 μg/kg and the relative standard deviation was 7.76％-37.81％.The method described here is suitable to measure the residue of Mei-ting in fish.