Abstract: Objective To discuss the effect of refined products of by alcohol elution on mice's acute toxicity. Methods Make the study on mice's acute toxicity of the refined products of Bupleurum Saikkosaponin by alcohol elution in accordance with classical acute toxicity test methods. Results Caculated by total saikkosaponin ,the LD50 of the refined products of by alcohol elution is 446.7 mg·kg^-1·, and the 95% confidence interval is 386.13～513.66 mg·kg^-1·d ^-1. The main acute toxicity symptoms and signs of dead mice are negligent action, then arising from unsteady gait, abdominal lying sleeping, rapid heart rate, shortness of breath, continuous convulsions, neurological inhibition, and eventually to death. The surviving mice's weight gainings are slow in 14d obervation period and there are noother obvious abnormalities. Conclusion The acute toxicity of refined products of Bupleurum Saikkosaponin by alcohol elution is bigger than the total extracts, and we further confirm that the total saikkosaponinis mainly toxical material basis of Bupleurum . The "dose-time-poison" relationships of accumulated toxicity are to be further studied.

Key words: total saikkosaponinis , separation and purification, mice, acute toxicity