Abstract: o establish LC-MS/MS method for the determination of Tylosin residues in aquatic products, we optimized the LC and MS conditions, pretreatment, separation and purification, used roxithromycin as internal standard and acetonitrile as extraction solution, purified the neutral alumina column, rotarily evaporated with isopropyl alcohol, dissolved and filtered, and finally injected into the instrument. The established method has a good linear relationship in the concentration range from 1.0 ngmL-1 to 500 ngmL-1 with coefficient greater than 0.998. The LOD and LOQ are 0.5 gkg-1 and 1.0 gkg-1, respectively. Moreover, we designed 3 spike tests with different concentrations in Carassius auratus, Penacus orientalis and Ctenopharyngodon idellus, and it is proved that their recoveries of standard addition and RSDs are 82.40%~100.70% and 0.86%~5.82%, respectively.