Abstract: A high-performance liquid chromatography-tandem mass spectrometric method was established for the determination of residue of malachite green (MG) in fishery products. MG and leucomalachite green (LMG) were extracted from homogenized samples with McIlvaine buffer-acetonitrile and acetonitrile for twice. After twice dichloromethane liquid-liquid extraction, the extracts were cleaned with PRS column. Analyte qualification were performed by electrospray ionization (ESI) in positive mode using MRM and the quantification were performed using internal standard method. The limit of detection was 0.10 gkg-1, and the linear range was 0.10~4.00 gkg-1. At spiked level of 0.10~4.00 gkg-1 of MG or LMG, the average recoveries of MG and LMG were 83.4% and 95.0%, RSD were 6.23% and 6.74%, respectively.