Abstract: Objective Compare the acute toxicity of different components of Fructus Bruceae. Methods Ig all-compo-nents,water extract and alcohol extract of Fructus Brucea to mice and test the LD₅₀ of oral dose in mice by the classic Methods of acute toxicity. The acute toxic symptoms were observed; the accumulated death number and the weight-changes of live mice were recorded. Results The LD₅₀ of all-components ,water extract and alcohol extract of Fructus Brucea to mice are 3.14g·kg^-1,4.023g·kg^-1,3.320g·kg^-1.They are respectively equal to 110 ,140.8,116 times of the daily dosage in clinical. Diarrhea and cyanosis are main acute toxic symptoms. Conclusion The size order of acute toxicity of different components in Fructus Brucea is all-components>alcohol extract>water extract. The toxical components and toxical mechanism should be researched furtherly.

Key words: Fructus Bruceae, all-components, water extract, alcohol extract, acute toxicity