Objective:To investigate the expression of androgen receptor(AR) and its correlation with molecular classifications in invasive breast cancer. Methods:The expressions of AR,estrogen receptor(ER),progesterone receptor(PR),human epidermal growth factor receptor-type2(HER2) and Ki67 in 635 cases of invasive breast cancer were detected with immunohistochemistry. The expression of AR and its correlation with molecular classifications,histologic grades and expressions of other related proteins was investigated and analyzed. Results:The positive rates of AR in luminal subtype A,luminal subtype B with negative HER2,luminal subtype B with positive HER2,HER2 over-expressing subtype,and triple negative subtype were 74.5%(137/184),56.1%(96/171),67.8%(40/59),56.0%(56/100),and 32.2%(39/121),respectively. The expression level of AR was lower in triple negative subtype than that in other subtypes(P<0.05). The expression of AR was significantly lower in adjacent tissues compared with invasive breast cancer tissues(P<0.05). There were no statistical difference in the expressions of AR with different age and different histologic grades(P>0.05). The expression of AR positively correlated with the expression of ER and PR(P<0.05),while negatively correlated with the expression of Ki-67(P<0.05). Conclusion:AR is expressed in different molecular classification of invasive breast cancer. Combined detection of AR and ER,PR,HER-2 may play an important role in predicting clinical outcomes of breast cancer.