Abstract: ObjectiveTo study the relationship between acute toxicity of Semen Euphorbiae and the content of fatty oil, and the reasonable fatty oil standard of Semen Euphorbiae Pulveratun. MethodsIg Semen Euphorbiae, fatty oil in Semen Euphorbiae, Semen Euphorbiae Pulveratun having different fatty oil(0%, 22.3％, 25.0％and 28.4%) to mice and test the weight and LD50 of oral dose by the conven-tional method for measuring acute toxicity. We compared the time and degree appearing the slight ill symptom such as lying, less food, wetting fur in mice. ResultsAll of the mice tested survive and the LD50 of oral dose to mice is not possible to determine. The maximum dosage of fatty oil in mice is 96g/kg/d and is 39.96g/kg/d either Semen Euphorbiae or Semen Euphorbiae Pulveratun for mice. The time for the occurrence of slight symptom and the degree in mice given Semen Euphorbiae Pulveratun having different fatty oil(22.3%, 25.0% and 28.4%) were different slightly. The more the fatty oil in Semen Euphorbiae Pulveratun, the earlier and the more serious appearance of the ill symptom. ConclusionThe fatty oil in Semen Euphorbiae is the main toxicity contents and the chief toxicity symptom of Semen Euphorbiae is diarrhoea and back bowing. A new standard for the safety content range of fatty oil of 18.0% ~ 22.0% is proposed for Semen Euphorbiae Pulveratun on the basis of the results given above and actual situation of frostlike powder processing of Semen Euphorbiae.

Key words: Semen Euphorbiae, Semen Euphorbiae Pulveratun, acute toxicity, the content range of fatty oil