The experimental myocardial damages were induced in Wistar rats by noradrenaline infusion (20ug/kg body wt/minute)for a period of 90 minutes daily for three consecutive days. The animals weresacrificed few minutes (acute phase), 7 days(subacute phase),and 30~90 days (chronic phase)afterinfusion. Specimens of myocardium were examined by histopathological, immunohistochemical and ultrastructural methods. Multiple focal necrosis, deficient of myoglobin in myocytes, myofibrillar fragmentation and dissolution were observed in the acute phase. The mdrphofogical feature simulated themyocardial infarctinn without coronary occlusion. Focal myocardial atrophy, scar f0rmation of myocardium, proliferation of fibroblasts and infiltraiton of the neo-colleagenous fibrils in necrotic myocytes were observed in the subacute and chronic phase. This feacture simulated the early cardiomyopathy.