Abstract:This article discussed the pharmacological effects of Yin-nourishing and Spirit-tranquilizing Liquid on thyroidism in animal with deficiency of yin.The results indicated that the formulae could significantly decrease T3 and T4 concentrations of serum,remarkably increase NE and 5-HT levels in the cerebral cortex and trunk as well as evidently decrease the contents of cAMP and increase cGMP in cerebral cortex in rat with deficiency of yin.The results provide scientific evidence for clinical treating insomnia with hyperactivity of fire due to yin deficiency type by the formulae.