The object of this study was to obtain acute information (single oral dose toxicity) of Taraxaci Herba (Dried total parts of Taraxacum platycarpum. H.Dahlstedt (Compositae)), has been traditionally used in Korean medicine for treating various inflammatory diseases. In order to observe the 50% lethal dose (LD 50), approximate lethal dosage (ALD) and target organs, test articles were once orally administered to female and male ICR mice at dose levels of 2,000, 1,000, 500 mg/kg according to the recommendation of Korea Food and Drug Administration Guidelines. The mortality and changes on body weight, clinical signs and gross observation were monitored during 14 days after single oral treatment of Taraxaci Herba aqueous extracts according to KFDA Guidelines with organ weights and histopathological observations of 12 types of principle organs. After single oral treatment of Taraxaci Herba aqueous extracts, we could not find any mortality and toxicological evidences up to 2,000 mg/kg treated group, the limited dosages in rodents at body and organ weights, clinical signs, gross and histopathological observations. Except for slight soft feces, which were detected in male mice treated with 2,000 mg/kg of Taraxaci Herba aqueous extracts at 1 day after end of treatment. The results obtained in this study suggest that the LD 50 and ALD of Taraxaci Herba aqueous extracts in both female and male mice after single oral treatment were considered as over 2,000 mg/kg because no mortalities were detected up to 2000 mg/kg that was the highest dose recommended by KFDA and OECD. However, it also observed that the possibility of digestive disorders, like diarrhea when administered over 2,000 mg/kg of Taraxaci Herba aqueous extracts in the present study, but these possibilities of digestive disorders can be disregard in clinical use because they ate transient in the highest dosages male only.