Objective To investigate the clinical significance of BRCA1/ 2 mutation in breast cancer patients with different malignant tumor family history. Methods We studied 98 cases of diagnosed breast cancer patients with malignant tumor family history. BRCA1/2 screening was performed by PCR-DHPLC sequencing method. All mutations were confirmed by using direct DNA sequencing. Results The prevalence of BRCA1/2 germline mutation was 20.41%.The BRCA1/2 mutation was 55.6% in patients with family breast and ovarian cancer, and was 20.0% and 17.9% in patients with family breast and in patients with ovarian cancer, respectively. In correspondence to 2 and 3 and 4 people withof the breast or ovarian cancer in family , the BRCA1/2 mutation was 16.25%、33.3%、66.67% ,respectively. Conclusion The BRCA1/2 mutation rate increased in the patients with breast and ovarian cancer family history, and the detection of BRCA1/2 mutation increased with the number of patients with cancer in a family.