Abstract:I. P. injection (5g crude drug/kg) of water extract of Puhuang (Typha orientalis) to S. D. rats can prevent ventricular fibrillation and sudden death caused by isoprotercnol and also arrhythmia induced by the infusion of BaCl2. Water extract of Puhuang can clearly increase the survival rate and also raise the dosage of BaCl2 infusion necessary to cause the death of animals.