Abstract: ［Abstract］Objective〖HTSS〗To study the expression of carcinoembryonic antigen related cell adhesion molecule 5（EACAM 5） and proliferating cell nuclear antigen（PCAN） in mucoepidermoid carcinoma（MEC） of salivary glands, and to investigate correlation with clinicopathological and prognosis of patients.
 〖WTHZ〗Methods〖HTSS〗The immunohistochemical streptavidin-perosidase（SP）was used to examine the expression of CEACAM 5 and PCNA in 55 MEC of salivary glands with different clinicopathological characteristics, 30 salivary pleomorphic adenoma（SPA）and 30 tumor adjacent normal tissues（control group）. The relationship of CEACAM 5, PCNA and clincal prognosis was analyzed.
 〖WTHZ〗Results〖HTSS〗Compared with SPA and control group, the positive expression of CEACAM 5 and PCNA were higher in MEC tissues（P＜0.01）. In MEC of salivary glands group, the positive level of CEACAM 5 and PCNA in pathological grade Ⅲ. The positive rates of CEACAM 5 and PCNA in MEC of salivary gland in TNM stage Ⅲ+Ⅳ were significantly higher than those in TNM stage Ⅰ+Ⅱ. The positive rates of CEACAM 5 and PCNA in MEC with lymph node metastasis were significantly higher than those without lymph node metastasis(P＜0.01). There were no significant difference among the positive expression of CEACAM 5 and PCNA in gender, age and tumor sites（P＞0.05）. The expression of CEACAM 5 was positive related to the level of PCNA in MEC tissues（P＜0.05）. The overall survival of the negative expression of CEACAM 5 and PCNA was significantly longer than the positive expression of CEACAM 5 and PCNA（P＜0.05）.
 〖WTHZ〗Conclusion〖HTSS〗CEACAM 5 and PCNA are highly expressed in MEC of salivary gland, which can co regulate the proliferation of tumor, affect the biological activity of tumor, and ultimately affect the prognosis of tumor patients.

Key words: salivary gland neoplasms, carcinoembryonic antigenrelated cell adhesion molecule 5, proliferating cell nuclear antigen