Objective : This study was to evaluate the single dose toxicity of Bojungikki-tang(Buzhongyiqi-tang, BJIKT) in male and female mice. Method : Aqueous extracts of BJIKT were administered to female and male ICR mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy ; organ weight and histopathology of 12 principle organs were examined. Results : we could not find any mortality, clinical signs, and changes in the body and organ weight. In addition, no BJIKT-treatment related abnormal gross findings and changes in histopathology of principle organs were detected except for some sporadic accidental findings. Conclusion : The results obtained in this study suggest that the 50% lethal dose and approximate lethal dose of BJIKT aqueous extracts in both female and male mice were considered as over 2,000 mg/kg, the limited highest dosage recommended by KFDA Guidelines, and can be safety used in clinics.