The effect of sedation was observed by sleeping method and the content of dopamine(DA) in hippocampal region of the experimental mice, which was measured by high performance liquid chromatography (HPLC). The structure of active ingredients was inferred by physical and chemical testing and HPLC-MS and NMR. The research showed that the active ingredient of hypnosis was the elution fraction of 70% ethanol in MCI, and it was Saponins, which were isomers of each other, with nitrogen(s) and a sugar chain consisting of three sugars.