This study was conducted to investigate the acute toxicity and safety of Pyungwi-san (Pingwei-san) in Sprague-Dawley rat though the current regulatory guideline. The preliminary study showed that the single oral administration of Pyungwi-san (Pingwei-san) did not induce any toxic effect at a dose level of 2000 mg/kg. Based on the results, 2000 mg/kg was selected as the limited dose. In this study, 10 rats of each sex were randomly assigned to two groups of 5 rats each and were administrated singly by gavage at dose levels of 0 and 2000 mg/kg. After single administration, Mortalities, clinical signs, body weight changes, gross findings were observed for the 15-day period. Throughout the study period, no treatment-related deaths were observed. There were no adverse effects on clinical signs, body weight, and gross findings at all treatment groups. These results showed that the single oral adminstration of Pyungwi-san (Pingwei-san) did not cause any toxic effect at the dose levels of 2000 mg/kg in rats. In conclusion, the $LD_{50}$ of Pyungwi-san (Pingwei-san) was considered to be over 2000 mg/kg body for both sexes.