Abstract: The invasion and metastasis of carcinoma of the floor of mouth（FMC） are closely related to its anatomical features. The floor of the mouth is located in the sublingual area，which is characterized by thin submucosa，multi-directional lymphatic flow and rich neurovascular innervation. The ducts of sublingual and submandibular glands directly open to the oral mucosa and keeps close anatomical relationship with surrounding tissues，organs and the multiple spaces in the maxillofacial region. The cancer of the floor of mouth has a high degree of malignancy， and surrounding organs invasion，peritoneal dissemination and lymphatic metastasis may occur in early FMC. Grasping the invasion and metastasis properties of FMC carcinoma from the perspective of anatomy will help to understand its clinical manifestations at different stage，to make proper treatment and to assess the prognosis of FMC.

Key words: carcinoma of the floor of mouth, anatomy, invasion, lymph node metastasis

摘要： 口底癌的侵袭转移与口底的解剖学特点密切相关。口底位于舌下区，具有薄弱的黏膜下层、丰富的淋巴回流和神经血管支配，舌下腺和下颌下腺导管也开口于此，且其与周围组织器官和多个间隙关系密切。口底癌恶性程度较高，早期即可发生周围组织浸润和颈部淋巴结转移。从解剖学的角度认识口底癌的浸润转移特性，将有助于理解该病不同病期的临床表现、制定合理的治疗方案及评估预后。

关键词: 口底癌, 解剖, 侵袭, 淋巴结转移