Objective. To assess the structure of the kidney in rats with alloxan diabetes mellitus (DM) following modulation of the macrophage functional activity. Material and methods. In 42 Wistar rats with alloxan DM (a dose of alloxan 300 mg/kg) with average weight 210 g, macrophage activity was modulated by administration of aminophthalhydrazide (2 mg/kg). In histological sections, the morphometric parameters of nephrons were studied, and the expression of Ki-67 in cells and of CD68 in macrophages was examined with immunohistochemical staining. The blood levels of glucose, glycated hemoglobin, insulin, urea, and creatinine were determined. Results. Modulation of macrophage activity in rats with diabetic nephropathy promoted an increase in the proliferative activity of the glomerular сell and tubular epithelial cells, a decrease in the percentage of damaged glomeruli. Conclusions. Modulation of the functional activity of macrophages can reduce the level of structural damage in the kidneys caused by diabetes in rats.