Intravenous injection of ferulidilol (0.5, 1.0, 1.5 mg kg -1 ) produced dose-dependent hypotensive and bradycardia responses in pentobarbital-anesthetized Wistar rats. Ferulidilol competitively antagonized (-)isoprenaline-induced positive inotropic and chronotropic effects of the atria and tracheal relaxation responses on isolated guinea pig tissues. The parallel shift to the right of the concentrationresponse curve of (-)isoprenaline suggested that ferulidilol was a β-adrenoceptor antagonist. The apparent pA 2 values were 8.04 ± 0.09 for the right atria, 8.03 ± 0.15 for the left atria, and 7.51 ± 0.06 for the trachea, respectively. Ferulidilol was more potent than labetalol. In thoracic aorta experiments, ferulidilol also produced a competitive antagonism of norepinephrine-and CaCl 2 -induced contraction with pA 2 and pKCa -1 values of 7.05 ± 0.03 and 6.04 ± 0.05, respectively. Ferulidilol produced cumulative relaxation responses on isolated tracheal strips from reserpine-treated guinea pigs. The effects were competitively antagonized by ICI 118,551 (10 -8 -10 -6 M), a relatively selective β 2 -adrenoceptor antagonist. The results implied that ferulidilol had partial β 2 -agonist activity. In the radioligand binding assay, ferulidilol produced dose-dependent inhibition of [ 3 H]CGP-12177 binding to rat ventricle and lung membranes with K i values of 3.40 and 17.94 nM, respectively. In addition, ferulidilol also antagonized [ 3 H]prazosin and [ 3 H]nitrendipine binding to rat brain membrane with K i values of 32.48 and 305.01 nM, respectively. These results further confirmed the α/β and calcium entry blocking activities of ferulidilol described in functional studies. Furthermore, ferulidilol (10 -8 -10 -5 M] inhibited lipid peroxidation induced by Fe 2+ and ascorbic acid, indicating that it possesses the antioxidant activity inherent in ferulic acid. Our results demonstrate that ferulidilol is a new generation α/βadrenoceptor blocker with ancillary calcium entry blockade, partial β 2 -agonist activities and additional antioxidant effects.