Abstract: Prior administration of "Styrax Pill for Coronary Disease" proper (6 components viz., styrax liquidus, Borneolum, Lignum santali, Aristolochia, Olibanum and Cinnabaris) or the mixture of Styrax liquidus, Borneolum, Lignum Santali and Olibanum to mice prolonged the survival time of the animals subjected to low pressure hypoxia. Styrax liquidus and Borneolum administered separately showed the same effect, whereas none of the other four components showed significant protection.A model of acute myocardial infarction was prepared by ligation of the left coronary anterior descending artery (LAD) in 24 dogs. Measurements of coronary sinus blood flow (CSF, ml/min), heart rate(HR), carotid artery blood pressure (BP, mmHg) and difference of oxygen contents between arterial and coronary sinus blood flow (MA-VO₂, Vol%) were made during the preligation control period, postligation ischemic period and one hour after treatment. Most of the LAD-ligated dogs showed progressive decreases of arterial blood pressure and CSF, accompanied by a somewhat persistent tachycardia and widening of the gradient between oxygen levels of arterial and sinus blood, that is, an increase of MA-VO₂ resulted. Treatment with "Styrax Pill for Coronary Disease" slowed the HR (average —37±5 beats/min), made CSF recover partially or completely (average +3.4 ±1.7 ml/min) and MA-VO₂ decreased (average—5.7±2.3 Vol%), but BP was maintained at the same level as the postligation period. Similar effects on HR, CSF and MA-VO₂ were produced by Styrax liquidus and Borneolum while Lignum santali, Aristolochia and Olibanum were ineffective.It appears that Styrax liquidus and Borneolum are the two active compositions which reproduce the cardiovascular actions of the "Styrax pill for Coronary Disease", while the other four components are ineffective. As a result of this study a new preparation composed of Styrax liquidus and Borneolum is now available for treating angina pectoris and is used clinically with promising results.