The pharmacokinetic properties and residue levels of amoxicillin (AMOX) were studied after intramuscular injection to cultured olive flounders (100±50 g), Paralichthys olivaceus. For pharmacokinetic studies, AMOX of 20 to 80 mg/kg body weight was administered at 17±2℃ or 22±2℃ and AMOX concentrations were determined in plasma, the liver, and the kidney by HPLC-UVD. Plasma samples were assessed at 0.25, 0.5, 1, 3, 6, 12, 24, 48, 72, 96, 168 hours post-dose, whereas liver and kidney concentrations were measured at 0.25 to 48 hours post-dose. The kinetic profiles of AMOX were analyzed by fitting to a 2-compartmental model with PKSolver program. The following parameters were obtained for a single dosage of 20, 40 and 80 mg/kg of body weight at 22℃ and 20 and 40 mg/kg of body weight at 17℃ in plasma, liver and kidney, respectively: Cmax (the peak concentration)= 27.23-257.36 ㎍/㎖, 5.49-41.65 ㎍/g, 16.75-129.31 ㎍/g; tmax (the time for peak concentration)= 0.05-0.91, 1.36-3.28, 1.95-4.49 h. For residue studies, AMOX of 40 and 400mg/kg was administered, and muscle samples were taken at 2, 5, 7, 14 and 21 days post-dose. The residueof AMOX in the muscle were found under the MRLs (maximum residue levels) within 7 days for the two doses.