Objective To study the expression and significance of CEA in occult micrometastasis ofcolorectal carcinoma. Methods 287 cases without metastatic lymph nodes were observed in 54 cases ofcolorectal carcinoma by immunohistochemical (LSAB) method. Results 15 cases of lymph nodes werefound with occult micrometastasis in 8 patients. All micrometastasis was positive in detection of CEA.Conclusion Detection of CEA was conducive to detect micrometastasis of lymphnode. It is significant forDukes staging,prognostic determination and treatment.