Abstract: Verticillatine (Vt) is a new alkaloid isolated from Rauwolfia verti-llata (Lour) Bail. In the present study the haemodynamic effects of Vt was investigated and compared with those of hexamethonium (C₆). In anesthetized dogs. intrayenous injection of Vt (0.0.5～1.0 mg/kg)induced a dose-dependent decrease of SBP, DBP, HR, CI, LVSP, LV dp/dt_max LVWI and TPR. The coronary blood flow and coronary artery resistance were slightly reduced, while the blood flow of the internal carotid artery and femoral artery increased and their vascular resistance lowered. After injection, of Vt (1 mg/kg), a decrease of myocardial extraction of oxygen and myocardial oxygen, consumption were observed. In anesthetized cats, following intravenouS injection of Vt and C₆ (2 mg/kg), the BP, LVSP and LVdp/dt_max were all decreased, but the LVdp/dt/p, CVP and LVEDP did not change. The effects of Vt were stronger and the duration of action was shorter than"those of C₆ These results indicate that Vt may have beneficial hemodnamic effects for the treatment of hypertensiion.