Purpose: Ojeok-san(Wuji-san) is one of the most frequently prescribed traditional medicine. To evaluate acute toxicity, ICR mice were treated with Ojeok-san(Wuji-san) administration. Methods: In this study, we investigated the acute toxicity of water-extracted Ojeok-san(Wuji-san). 0(control group), 1250, 2500, and 5000 mg/kg of Ojeok-san(Wuji-san) were orally administered to 20 male and 20 female for 14 days. We observed survival rates, general toxicity, change of body weight, and autopsy. Results: Compared with the control group, we could not find any toxic alteration in all treated groups (1250, 2500 and 5000 mg/kg). Conclusions: $LD_{50}$ of Ojeok-san(Wuji-san) might be over 5000 mg/kg and it is very safe to ICR mice.