Abstract: Objective To investigate the expression of MGMT and XRCC1 in invasive ductal carcinoma(IDC),and to explore the relationship between clinical factors.Methods Immunohistochemistry(S-P)was performed for MGMT and XRCC1 on 72 specimens of IDC,30 specimens of benign breast lesions.Results The positive expression rate of MGMT in IDC was 70.8%,lower than which expression in benign breast lesions,which had correlation with pathological grades of invasive ductal carcinoma(IDC)and the expression of ER and p53(P＜0.05).The positive expression rate of XRCC1 was 52.8%,lower than which expression in benign breast lesions,which had correlation with the pathological grades of IDC.Conclusion They were important pathological signs to evaluate the malignancy degree and prognosis of the breast cancer.These markers play an important role in making sure the treatment prescription for breast cancer patients.