The microvascularization of the layers of the tunica vaginalis propria testis in juveniles and youths is different in morphological parameters which is responsible for their participation in metabolic processes. The distribution of vessel diameters is based on the regularity of random variation. The number of classes for each link of the microcirculatory bed in the tunics studied practically coincide. In any microvascular part of the parietal and visceral layers of the vaginal tunic of the testis a class (a leading functional group of vessels) may be established which has substantially greater density than that of other classes of the variation line presented. The results of morphometry show the prevalence of the venular portion over the arterial one in each of the layers under study. However, the difference between the venular and arterial portions of the microcirculatory bed is more considerable in the parietal layer which is sure to influence the degree of its outflow from the microvascular system.