The extracts of Euphoria longan, Ziryphus jujuba, Thuja orientalis, Polygala tenuifolia, Acorus gramineus, Cyperus rotundus, Poria cocos, Uncaria rhynchophylla, and Albizzia julibrissin, which have been used as sedative drugs in Korean folk medicine, were evaluated for their effects on neurotransmission and antioxidative system in vitro. Among the tested drugs, Acorus gramineus showed most inhibitory activities on monoamine oxidase, xanthine oxidase, aldehyde oxidase, and lipid peroxidation and Uncaria rhynchophylla also inhibited most effectively GABA transaminase and DPPH radical.