[Objective] The aim of the study is to seek a good anesthetic to Fenneropenaeus chinensis. [Method] The anesthetic effect of eugenol to juvenile Fenneropenaeus chinensis was investigated. [Result] The juveniles could be effectively anaesthetized by 50-400 mg/L eugenol aqueous solution with temperature of 24 ℃. Within the concentration range of 50-400 mg/L, the increase of the eugenol concentration could shorten the time required for anesthesia, meanwhile could prolong the time for recovery. The recovered rate of prawn reached 100% when the eugenol concentration was lower than 200 mg/L, while the recovered rate of prawn was just 66.67% when the eugenol concentration was higher than 400 mg/L. The survival rate of prawns in test group was 100% from the observation of three consecutive days. For the specific dose, the anesthetic effect enhanced with the increase of water temperature (18-27℃). [Conclusion] Eugenol is a safe and efficient anesthetics that can be applied in genetic breeding of prawn.