Abstract: Objective：To investigate cardiac structure and function，myocardial cell morphology，and myocardial fibrosis in ovariectomized rats. Methods：Female Sprague-Dawley rats were divided into 2 groups，sham-operated group（Sham group） and ovariectomized group（OVX group），each group has 10 rats. The OVX group underwent bilateral oophorectomy. The 2 groups have undergone UCG to evaluate cardiac structure and function. The heart tissue of each rats were taken HE and Masson staining，to evaluate myocardial morphological changes. Results：Compared with the Sham group， left ventricular septal of OVX group was significantly thicker （P＜0.05）；OVX rats′ myocardial cells area increased significantly（P＜0.01）；ovariectomized rats′ cardiac collagen volume fraction and cardiac perivascular collagen area increased significantly （P＜0.05）. Conclusions：In ovariectomized rats，left ventricular septal and posterior wall have been significant thickening，reconstruction change appeared both in myocardial cells and interstitial collagen.

Key words: Climacteric, Endomyocardial fibrosis, Cardiovascular diseases, Echocardiography, Ovariectomized rats