Abstract: Objective: To investigate the expression level of E2F3、AR in prostate cancer(PCa) and discuss their significance in carcinogenesis and progression of PCa, as well as their relationship with the clinical stage and pathologic grade and their correlation with each other. Methods: The expression of E2F3、AR was detected by immunohistochemistry (IHC) in tissues from 50 cases of prostate cancer and 50 cases benign prostatic hyperplasia (BPH) , The relationship with the clinical stage and pathologic grade and their correlation with each other by was analyzed by SPSS 13.0.Results:1.The rate of positive E2F3 for BPH and prostate cancer was 20%(2/10)and 66%(33/50) respectively. The expression level of E2F3 in prostate cancer was higher than that in BPH(P<0.0001)，and it was related positively with clinical stage(P<0.001)and pathological grade(P<0.020) in prostate cancer. 2. The rate of positive AR for BPH and prostate cancer was 90 %(9/10) and 82%(42/50) respectively. The expression level of AR in prostate cancer was low than BPH(P<0.0001)，and it was related negatively with clinical stage (P<0.0004) and pathological grade(P<0.0005) in prostate cancer.3. The expression level of E2F3 in PCa was uncorrelated with AR expression（rs=-0.017,P>0.05）. Conclusion: E2F3 may play an important role in the onset and progression of prostate cancer by the cell cycle pathway.E2F3 can promote prostatic cell proliferation.

Key words: Prostatic cancer, E2F3, AR