Abstract: This study compared the penetration effects of two common penetration enhancers (PE) (Acorus tatarinowii essential oil and water soluble azone) with different mass fractions (1%, 4%, 7%, 10% and 1%, 3%, 5%, 10%) on the juvenile Lateolabrax maculatus absorbing eugenol and MS-222. The results show that: 1) PEs could reduce the time of anaesthesia and recovery significantly, and reduce the dosage of anesthetics to achieve similar anesthetic effects. 2) With increasing mass fraction of PE, the penetration effect first enhanced and then weakened. 3) The optimal mass fraction of penetration of A. tatarinowii essential oil and water soluble azone on eugenol or MS-222 were 7% and 3%, respectively. According to the antioxidant index of the gill tissue, we found that: 1) After soaking the fish in the anesthetics, the activities of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) and the concentrations of malonaldehyde (MDA), glutathione (GSH) increased in the gill tissue of L. maculatus (P<0.05). 2) The activities of SOD, CAT and the concentrations of MDA and GSH in the gill tissue of the PE anesthesia group were significantly lower than those of the control group (P<0.05).