Abstract: Objective:To explore the expression of breast cancer resistance protein(BCrP)and its significance in immortalized cell lines of tongue carcinoma with lymphatic metastasis.Methods:The immortalized cell line(Tca8113-Ml)was harvested by isolating and culturing from lymph node of lymphatic metastasis nude mice.The lymphatic metastasis model were established by injecting Tca8113-Ml into the nail pad of nude mice,and the control group were injected with stroke physiological saline solution.Lymph nodes of two groups were harvested after 4 weeks.The expression of BCrP in lymph node was detected by immunohistochemical stain.Results:The positive expression of BCrP in the lymph node of model group was observed by immunohistochemical staining,the positive rates of which was 27% to 35%.There was no expression of BCrP in the control group.Conclusions:Cancer stem cells areseed cellsof the metastasis and recurrence of cancer.The expression of stem cell marker BCrP in metastasizing lymph node of tongue carcinoma can provide the theory basis for further invesigating the cancer metastasis and drug resistance.