In the spontaneous hypertensive rats (SHR)--line NISAG--most cardiac hystiocytes of the left ventriculum have signs of ultrastructure damage to a variable extent. First of all the contractile and energetic function of cardiac hystiocytes has different abnormalities. Administration of Lipril (20 mg/kg daily, during three months) showed the normalization of the ultrastructure of myocardium of SHR. This was evident through decreased in overcontractility of muscular fibrils till complete or partial disappearance of structuring sarcomers. Most mitochondria preserve ultrastructural organization. There are practically no damages in the endothelium, except non-significant vasoconstriction. The comparative analysis of the ultrastructural changes of cardiac hystiocyte of SHR after 3 months of treatment of Lipril showed that current medication has the recoverable effect on the structural organization of cardiac hystiocytes, mitochondrion and blood vessels.