An electromagnetic flowmeter probe was chronically implanted around the ascending aorta in a group of dogs. Subsequently, ten dogs were lightly anesthetized with halothane (0.75%) and the third (aqueous) extract of ginseng (40 mg/kg) was administered intravenously. Five dogs were anesthetized without the administration of ginseng. Eleven cardiovascular variables including cardiac output, stroke volume, heart rate, mean arterial pressure, pulse pressure, central venous pressure, total peripheral resistance, pH, PaCO2, PaO2, and base deficit were compared. The cardiac output, stroke volume, and central venous pressure were decreased significantly, while total peripheral resistance was increased significantly following ginseng.