Abstract: The current study investigated the residue elimination of enrofloxacin and its metabolite ciprofloxacin in Larimichthys crocea at multiple dosages to provide a reasonable dosing plan and withdrawal period for the aquaculture industry of L.crocea.The concentration of enrofloxacin and its metabolite ciprofloxacin in the plasma,muscle and liver of L.crocea after a 5 days consecutive dose of 25 mg/kg body weight at water temperature of(20±3)℃ were detected by high performance liquid chromatography tandem mass spectrometry method.The results showed that the peak concentration of enrofloxacin in L.crocea was fast reached after dosage,while the peak time of enrofloxacin in plasma,liver and muscle were 8 h,12 h and 12 h,respectively.The peak concentration of enrofloxacin in plasma,liver and muscle were 3.068 mg/L,3.446 mg/kg and 4.089 mg/kg,respectively.The peak time of ciprofloxacin in plasma,liver and muscle were 8 h,12 h and 8 h,respectively,and the peak concentration of ciprofloxacin were 0.104 mg/L,0.753 mg/kg and 0.355 mg/kg,respectively.Enrofloxacin metabolized less ciprofloxacin in L.crocea.The withdrawal time of enrofloxacin in L.crocea should not be less than 18 days under this experimental condition.