Objective. To determine the effects of losartan and captopril treatment on ventricular remodeling and function after myocardial infarction in rats. Methods. Thirty-two rats with MI induced by coronary ligation after seven days were divided into four groups randomly and treated with captopril（2 g. liter-1

group A）

losartan（10 mg. kg-1. d-1

group B）

losartan（30 mg. kg-1. d-1

group C） and placebo （no drug

group D） for six weeks

respectively. Shamoperated rats（group E）served as controls. Echocardiography was performed at 1 and 7 weeks after MI

re- spectively. Results. Compared with the results before treatment

both LV end-diastolic internal diameter and volume decreased significantly and the thickened Posterior wall was reversed in group A

B and C; the peak early filling velocity decreased whereas the peak velocity was increased in these three groups. There are no significant difference among the three treated groups. However

LV end-diastolic internal diameter and the E/A were still increased

whereas the thickness of anterior wall and the peak velocity of LV outflow were decreased in group A

B

and C after treatment comparing with group E. Conclusion. Both angiotensin converting enzyme inhibitor and angiotensin II receptor antagonist can prevent the ventricular remodeling and improve the ventricular function.