Objective To study the expression and clinical significance of BRCA1 and BRCA2 in sporadic breast cancer in women of Jiaodong peninsula. Methods Immunohistochemistry and tissue array were used to detect the expression of BRCA1 and BRCA2 in 100 cases of sporadic breast cancer and 30 cases of benign breast tumor in women of Jiaodong peninsula. Results ① The expression rate of BRCA1 and BRCA2 was 49% (49/100) and 50% (50/100) in breast cancer, 80% (24/30) and 83.33% (25/30) in benign breast lesions respectively. The expression rate of BRCA1 and BRCA2 in breast cancer was lower than that in benign breast lesions (P<0.05). ② The expression of BRCA1 and BRCA2 was uncorrelated with factors such as tumor size, lymphatic metastases, age and menopause or not(P>0.05). ③ There was no dependency between the expression of BRCA1 and BRCA2 (P> 0. 05). Conclusions The expression rate of BRCA1 and BRCA2 in breast carcinoma in women of Jiaodong peninsula was lower than that in benign breast lesions, suggesting that the expression of BRCA1 and BRCA2 was related to the occurrence of sporadic breast carcinoma in women of Jiaodong peninsula. However, the role of BRCA1 and BRCA2 in the genesis and development of the breast carcinoma is independent.