Abstract: To study the pharmacokinetic characteristics and residue elimination of eugenol in the plasma and muscle of tilapia,at water temperature of(25±1)℃,tilapia was anesthetized with 20 mg/L eugenol solution for 24 hours,then the plasma and muscle samples were collected respectively by time period.The eugenol residues in the plasma and muscle of tilapia were determined,to determine the pharmacokinetics parameters and metabolic processes of eugenol in tilapia.Result showed that the plasma and muscle concentration-time course of eugenol both conformed to a one-compartment open model with the first order absorption.The pharmacokinetic equations were as follows:C_plasma=4.762(e^{-0.062 6 t}-e^{-0.064 7 t}),and C_muscle=1.089(e^{-0.006 9 t}-e^{-0.002 17 t}).The main pharmacokinetics parameters in plasma were:T_1/2kawas 14.06 h;T_1/2kewas 14.68 h;and C_maxwas 5.18 mg·kg^-1.The main pharmacokinetics parameters in muscle were:T_1/2kawas 84.80 h;T_1/2kewas 101.48 h;and C_max was 3.07 mg·kg^-1.The absorption and eliminate speed in plasma were faster than in muscle.According to the maximum residue limit(MRL)of 0.05 mg/L,the withdrawal period should not be less than 12 days under this experiment condition when muscle was selected as target tissue.So eugenol was not recommended as an anesthetic for transportation of tilapia.