Abstract: Objective To establish the orthotopic model of Cal27 tongue squamous carcinoma cells.Me thods 2×106 Cal27 cells suspension was injected into floor of mouth of nude mice. Then the tumor volume was measured periodically and the body weight of the nude mice was recorded. 14 days later, nude mice were killed, and the primary tumor and adjacent tissues, lungs, and liver were harvested. The tissue sections were stained with hematoxylin and eosin. The submandibular lymph nodes and lung, liver metastasis, and statistical metastasis rate were observed. Re s ults The tumor formed after day 3 that nude mice were inoculated with Cal27 cells, and tumor formation rate was 100% (24/24) . HE staining showed tumor tissue had typical performance of squamous carcinom. The squamous carcinoma cells were found in the submandibular lymph nodes, and the metastasis rate was 70% (17/24) . There were no metastasis found in liver and lung. Conclus ions Orthotopic metastatic model of oral cancer in nude mice has been established successfully. This animal model can objectively reflect the biological behavior of human oral cancer, is one of the ideal methods to study the invasion and metastasis of oral squamous cell carcinoma.