In 74 white rats by means of non-injection++ method morphofunctional state of the myocardial capillary bed has been studied in dynamics at occlusion of descending branch of the left coronary artery. During the first week after the operation blood supply of the areas, adjoining the necrosis, increases at the expense of dilatation and some increase in number of functioning capillaries, that results in enlargement of the exchanging surface and capacity of the capillary bed. Beginning from the 12th day, the value of all these parameters decreases, however, they do not reach their initial level. By the end of the experiment (45 days) the number of the functioning capillaries somewhat decreases, but the capillary diameters remain increased. By that time in the myocardial areas, adjoining the necrosis a parviansiform capillary network without a definite orientation, concerning muscle fibers, has been formed.