The acute toxicity and sedative activity of flavonoids and saponin isolated from Zizyphus seeds have been evaluated in mice. All the compounds elicited potentiation of hexobarbital-induced hypnosis, inhibition of ladder-climbing and caffeine-induced hyperactivity. Swertisin was the most potent of all flavonoids tested. The potency of saponin in these tests was found to be higher than that of swertisin. The activities in rotarod test and electroshock seizure test, on the other hand, were relatively weak or nil. From these findings it was suggested that flavonoids and saponin from Zizyphus seeds have neuroleptic activity without anticonvulsant or muscle relaxant activity accompanied by neurological deficit.