A new model of lymph node metastasis was successfully established by serial transplantation of a metastatic tumor to the submandibular lymph node from a chemically induced squamous cell carcinoma of the tongue into the buccal pouch in hamsters. Tongue carcinomas were induced by application of a 0.5% solution of 9,10-dimethyl-1,2-benzanthracene (DMBA) in acetone. The tongue tumors and metastatic tumors to the submandibular lymph nodes were transplanted to the buccal pouch of recipient hamsters. In the first generation, lymph node metastases were found only in hamsters that received a metastatic tumor. The metastatic tumors to the lymph nodes were maintained by serial transplantation into the buccal pouch from metastatic sites until the eleventh generation. The incidence of lymph node metastasis exceeded 90% in animals after the ninth generation.