Abstract: AIM: To study the therapeutic effect of oxyphenamone on heart failure. METHODS: An acute heart failure model was established by giving sodium pentobarbital iv at the dosage of 30～60 mg.kg-1 in guinea pigs, cats and dogs. RESULTS: Intravenous injection of oxyphenamone(1～8 mg.kg^-1) dose-dependently increased myocardial contractile force, left ventricular systolic pressure, ±dP/dt_max, cardiac output, left ventricular work and the blood flow of the coronary and femoral arteries. The cardiotonic effect of oxyphenamone was similar to that of phosphodiesterase inhibitors(PDEI) amrinone and milrinone. The differences between these two agents include that oxyphenamone increases mean arterial pressure(MAP) and decreases heart rate(HR) in animals with heart failure, but PDEI induces inverse effects on MAP and HR and is prone to produce arrhythmia. CONCLUSION: The results suggest that oxyphenamone is more beneficial for the treatment of heart failure.