The effects of various tannins and related compounds on the adrenaline-induced lipolysis in fat cells isolated from rats were investigated. Hydrolyzable tannins such as geraniin, corilagin, tellimagrandin I, mallotusinic acid, chebulinic acid, alnusiin and pedunculagin inhibited the adrenaline-induced lipolysis. Condensed tannins such as Ss-tannin 1 and RSF-tannin H showed weak inhibitory effects on the adrenaline-induced lipolysis. Based on these results, the relationship between the structures and physiological actions of these tannins is discussed.