OBJECTIVE To investigate the expression of cyclin D1, ER, and PR gene proteins and to analyze their relevance to tumor biological characteristics, chemotherapy effects, diseases free survival (DFS) and overall survival (OS) of patients. METHODS Immunohistochemical staining techniques was used to detect the expression of cyclin D1, ER and PR gene protein in 100 samples of breast infiltrating ductal carcinoma patients, all female, aged 49.49 +/- 10.81 (28 approximately 92). RESULTS The positive expression rate of gene protein was 60& for ER 58% for PR, and 55% for cyclin D1 ER, PR presented a negative correlation to SBR grading. Patients with cyclin D1 positive tumor had longer OS than those with cyclin D1 negative tumor (P = 0.0053). Coexpression of cyclin D1 and ER was significantly correlated with longer DFS and OS (P(dfs) = 0.0108, P(os) = 0.0030). The positivity of ER and PR was significantly correlated with longer DFS (P(ER) = 0.0322, P(PR) = 0.0129). For those patients receiving postoperative adjuvant chemotherapy, the expression of ER and PR were correlated with a better prognosis and longer DFS. The patients with cyclin D1 negative tumor, who received CAF, had a mean DFS of 51.6 months and a mean OS of 57 months in comparison with 24.8 months and 31.2 months for those patients who received other chemotherapy. CONCLUSION In breast infiltrating ductal carcinoma patients expression of ER and of PR are correlated with longer DFS, cyclin D1 expression is correlated with longer OS. For the patients receiving postoperative adjuvant chemotherapy, the expression of ER and PR correlated to a better prognosis and longer DFS. The patients with cyclin D1 negative tumor who receive CAF chemotherapy have longer DFS and OS than those receiving other chemotherapy.