Vascular architecture of tumors in experimental animals has been studied in detail. However, the reports on architecture of the capillaries in human carcinoma in the head and neck regions are few nowadays. In this paper architecture of the blood vessels reproduced by using methacrylate casting medium in human carcinoma of the tongue was studied by scanning electron microscopy. Tortous capillaries and loop-like vessels were observed at the proliferative area of the tumor on the surface of the tongue. There were avascular zones around the vessels of the tumor characterizing irregular proliferation. The vessels of sinusoidal, tapering, distorted and disrupted characters were seen in the muscle layer of the tongue. Ruptured vessels and viable tumor-cells were observed at the areas surrounding necrotic lesions. These findings elucidated combination of various kinds of architectures of vessels in various stages of tumor-growing. Existence of the avascular area suggests that proliferation of tumor-cells proceeds before proliferation of the capillaries. Both avascular and necrotic changes in the structure might reduce the effects of anti-cancer agents.