The authors report on the method of determination of the weight indices of the adrenyl gland glomerular, testicular-reticular and medullar zones with a spheroid shape; it is substantiated by mathematical analysis of a plasticine model of the adrenal gland, whose characteristics approached the actual ones. The method was particularly accurate in determination of the weight of the fascicular-reticular and glomerular zones, and less--in determination of the weight of the medullary layer, the method's error being 0.6-0.9% in the first case, 2.7-3.5% in the second and 5.3-6.4 in the last.