Background Transplanting a vascularized autologous submandibular gland (SMG) is considered an effective method to treat severe keratoconjunctivitis sicca. But the operation may fail due to the anatomic variances in the blood vessels of SMG. The present study aimed to investigate the submandibular glands at the microanatomy level. Methods The microanatomy of blood vessels including arteries and veins of submandibular gland was investigated using 30 adult corpses and 60 submandibular glands were anatomized under a surgical microscope. The lengths and diameters of the arterial and venous glandular branches were measured using sliding caliper. Results The submandibular gland was mainly supplied by the facial artery and submental artery, partly by the lingual artery and external jugular artery. The venous drainage of the submandibualr gland occurred through the anterior facial vein, the venae comitantes of facial artery, the vein close to the Whaston's duct (the hilum vein), and seldom drained to external jugular vein and other veins. Conclusions The anatomy of SMG is a complicated structure. Determining the main blood vessels of the submandibular gland is very important to achieve a successful vascularized autologous SMG transplant.