The microvasculature of the submandibular glands of guinea pig's was studied with the replica-SEM msthod. Special attention was paid to the microvascular architecture around the glandular ductal tree, which is mainly dichotomous, but usually asymmetrical and irregular, with a divergent angle of 40-80? and 7-8 grades of branching. The ductal tree is surrounded with a periductal vascular plexus. The periductal plexus of the excretory ducts can be divided into two layers: the inner layer is formed by capillaries and the outer layer by veins, so called venous coat. This venous coat is complexly constructed with button veins, loop veins and complicated venous circulatory by-passes. The capillary plexus of the striated ducts and intercalated ducts is supplied by venules with the cha-ractristics of the portal vein as they come from the capillaries of the acini. There are complex A-V and V-V anastomoses at the venous coat and at the lobu-lar porta.The significance of the microstructures described above was discussed.