Abstract:The safety and feasibility of Menyanthes trifoliate L.as a tranquility food was explored.The maximum tolerated dose method was used to calculate the acute toxicity.And locomotor activity assay was used to evaluate the sedative and hypnotic activities.The effective of M.trifoliate extract and different polar parts on the sleep rates，the sleep latency and duration of sleep in model mice were compared by injecting subthreshold dose and suprathreshold dose of pentobarbital sodium.The maximum tolerated dose（MTD）of the acute toxicity of extract from M.trifoliate was higher than 10 g/kg.The day of administration had a slight effect on the body weight of the mice，and returned to normal on the second day，and no abnormal lesions were found in the organs.The ethyl acetate fraction and the n-butanol fraction of M.trifoliate could obviously inhibit the locomotor activity of mice.The high dose of ethyl acetate fraction and the high，low dose of n-butanol fraction of M.trifoliate could increase the percentage of sleeping.The high，low dose of ethyl acetate fraction and the high，low dose of n-butanol fraction of M.trifoliate could decrease the sleep latency and prolong the sleeping time of mice.The extract of M.trifoliate showed low acute toxicity and great sedation-hypnotic activity.The n-butanol extract and ethyl acetate extract were the sedation-hypnotic active site.