Abstract: Objective To investigate the rules and related factors of occult neck lymphatic metastasis of tongue cancer, and the influence of different neck dissections on the prognosis to provide evidence for choosing suitable operation methods. Methods The data of 87 cN0 tongue cancer patients who had been diagnosed as squamous cell carcinoma were collected in Head and Neck Surgical Department, Guangxi Medical University Affiliated Tumor Hospital from January 1, 2002 to August 31, 2009. They didn't receive radiation or chemotherapy before surgery. Univariate analysis was applied to analyze the correlation between occult cervical lymph node metastasis and age, gender, preoperative disease duration, depth of primary tumor invasion, T stage, histological grading. Multivariate analysis was used to analyze prognostic factors for cN0 tongue cancer patients, distribution rules of occult cervical lymph node metastasis, and different methods of neck dissection. Results Univariate analysis showed that the difference was not statistically significant in the effect of sex, age or preoperative disease duration(P>0.05) whereas significant in the effect of primary tumor invasion depth, T stage and histological grade(P<0.05) on patients with occult cervical lymph node metastasis from cN0 tongue cancer. Multivariate analysis showed that only T stage was the independent factor for the prognosis of cN0 tongue cancer patients. The factors of different neck dissections had no significant difference(P<0.05). Conclusion Invasion depth of primary tumor, T stage and histological grading are closely related to cN0 tongue cancer patients with occult lymphatic metastasis, therefore,they could be the predicted indexes; cN0 tongue cancer has a high rate of occult lymph node metastasis. The most common metastasizing area are levelⅠ,Ⅱand Ⅲ of the Ipsilateral neck; we recommend the selective neck dissection under that circumstances.