Abstract: Objective :To detect the breast cancer micrometastases in peripheral blood by using hMAM mRNA and CEA mRNA RT-PCR. Methods :Expression of hMAM mRNA and CEA mRNA in peripheral blood were detected in 52 cases of breast cancer, and 28 patients with breast benign lesions and 10 heathly volunteers as conrols by RT-PCR. Results :The potisve hMAM mRNA and CEA mRNA expession were 30.8Q and 34.6%. No positive hMAM mRNA and CEA mRNA were found in peripheral blood of 28 patients with breast benign lesions and 10 heathly volunteers. hMAM mRNA and CEA mRNA expession were correlated with axillary lymph nodes status and TNM stage. There were no significant differences between micrometastases positive and negative groups among any of other clinical parameters. Conclusion :hMAM mRNA and CEA mRNA may be potential tumor markers for detecting micrometastasis and recurrence in peripheral blood.