Abstract: After intravenous infusion of acart 60 mg/kg/min or cart 50 mg/kg/min for 5 min, both of them exhibited positive inotropic, negative chrontropic action and vasodilation on experimental heart failure induced by sodium pentobarbital in anesthetized dogs as well as rabbits. When acart or cart in combination with stro-k was administered to dogs with heart failure, there was a delayed onset of arrhythmia induced by stro-k and an increase of the "safety margin" of stro-k. The above mentioned actions of acart is significantly larger than that of cart. In rabbits with heart failure, the positive inotropic action of acarn 60 mg/kg/min for 5 min in combination with stro-k (60μg/kg) was more powerful than that of each alone. This phenomenon was considered as synergetic action. The action of acart plus stro-k was larger than that of cart plus stro-k, but there was no significant difference between the two groups.