Objective To investigate the expression of presenilin-2(PS2) and glutathione S transferase π(GSTπ) and their role in the prognosis and therapy of infiltrating ductal breast carcinoma. Methods The expression of PS2 and GSTπ in tumor tissues from 210 patients with infiltrating ductal breast carcinoma confirmed by pathologic examination and treated with modified radical mastectomy was examined by using LSAB immunohistochemical method. Results The expression rate of PS2 was 49.5%(104/210) and the expression rate of GSTπ was 48.1%(101/210). The grade of the postoperative 5-year survival rate and 10-year survival rate in four groups of 210 patients, from high to low, was the group 1 (PS2 positive expression/GSTπ negative expression), the group 2 (PS2 positive expression/GSTπ positive expression), the group 3 (PS2 negative expression/GSTπ negative expression) and the group 4 (PS2 negative expression/GSTπ positive expression). Conclusion The prognosis of the group 1 is the best, the group 2 better, the group 3 good and the group 4 the worst. The results suggest that reasonable use of endocrinotherapy and chemotherapy in infiltrating ductal breast carcinoma is necessary.