Abstract: Objective To discuss the effect of refined products of Bupleurum saikosaponin by alcohol elution on rat's acute toxicity. Methods Make the study on rat's acute toxicity of the refined products of Bupleurum saikosaponin by alcohol elution in accordance with classical acute toxicity test methods. Results Caculated by total saikosaponin the LD50 of the refined products of Bupleurum saikosaponin by alcohol elution is 591.95 mg·kg^-1·d^-1, and the 95%(,) confidence limit is 490.96～713.7 mg·kg^-1·d^-1. The main acute toxicity symptoms and signs of dead rats are negligent action,then arising from unsteady gait, abdominal lying sleeping, rapid heart rate, shortness of breath, ontinuous convulsions, neurological inhibition, and eventually to death. The surviving rats' weight gainings are slow in 14d obervation period and there are no other obvious abnormalities. The acute toxicity of refined products of Bupleurum saikosaponin by alcohol elution is bigger than the total Bupleurum saikosaponin extracts,but it's smaller than the mice's. Conclusion The total saikosaponin is mainly toxical material basis of Bupleurum . The toxical location and mechanismare to be further studied.

Key words: total , separation and purification, rats, acute toxicity