Abstract: Objective To confirm whether hMAM is a mammary-specific marker, and to investigate the relationship between the hMAM expression and the clinicopathologic characteristics, and to estimate the prognostic value of hMAM. Methods One humdred and Forty-two primary breast cancer patients between 1996 to 2003, 103 various organ tumors,30 normal breast tissues and 30 benign breast tumors were analyzed by immunohistochemical assay. Results hMAM was detected in 70.4% primary breast cancer patients, and its expression was associated with positive expression of ER, but not with age,pathologic type,HER2 status,tumor size, clinicopathologic stage, or PR status. Kaplan-Meier survival analysis explored a significant difference between hMAM-positive and hMAM-negative expression, and the former had a better outcome. COX multivariate analysis revealed that pathologic stage, ER expression, age and hMAM significantly and independently affect overall survival. Conclusion hMAM was highly expressed in breast cancer patients and have an ideal sensitivity and specificity. Survival curve revealed that hMAM was a independent prognostic factor for primary breast cancer patient's outcome.