<正> Flavonoids are found ubiquitously in higher plants and constitute an importantcomponent of the majority of peoples' daily diets.The biological activities offlavonoids cover a very broad spectrum,from anticancer and antibacterial activi-ties through to inhibition of bone resorption.In the present paper,the interac-tions between flavonoids and lipid bilayers as well as biological membranes andtheir components are reviewed,with special emphasis on the structure-activityrelationships and mechanisms underlying the biological activity of flavonoids.