Pharmacological activities of the effective constituents: essential oils, flavonoids andalkaloids, in fruit of Citrus aurantium L. were compared. Blood pressure was increased markedly by transfusion of the alkaloids. Contractions of isolated intestines were iuhibited byflavonoids. Essential oils significantly decreased the rate and frequency of writhing syndromeinduced by ip acetie acid and spontaneous locomotor activities in the mice with the exceptionfexciting at first followed by inhibiting the isolated intestines,which displayed analgesia andoceutral inhibition to a certain extent.