In this study, we investigated the single dose toxicity and safety about water-extracted Galgeuntang. To evaluate single dose toxicity, 20 male and 20 female ICR mice were observed survival rates, general toxicity, changes of body weight for 14 days after single oral administration of 0 (control group), 1250, 2500 and 5000mg/kg Galgeuntang. And after 14 day, We observed autopsy. Compared with the control group, we could not find any toxic alteration in all treated groups (1250, 2500 and 5000 mg/kg). LD50 of Galgeuntang might be over 5000mg/kg and it is very safe to ICR mice.