【Abstract】 Objective To investigate the expression and clinical significance of androgen receptor associated factor (ARA) 54 and apoptotic protease activating factor (Apaf) in patients with prostate cancer. Methods 76 prostate cancer patients admitted to our hospital from January 2015 to may 2018 were selected as prostate cancer group, and 36 cases of benign prostatic hyperplasia in the same period were selected as prostate hyperplasia group. The expression of ARA 54 and Apaf were detected by immunohistochemistry and real time quantitative polymerase chain reaction (RT PCR) (SYBR staining). Gleason scoring method was used to evaluate the clinical stages of patients. Spearman correlation analysis was used to analyze the correlation between the clinical stages and the expression level of ara54 and Apaf. Results The positive levels of ARA 54 and Apaf in prostate cancer group were significantly lower than those in BPH group (P＜0.05), and the positive levels of TGF β were significantly higher than those in BPH group (P ＜0.05). There was a significant difference between the positive expression of ARA 54 and Apaf in pathological grade, clinical stage and distant metastasis(P ＜0.05). The results of Spearman correlation analysis showed that there was a positive correlation between the expression level of ARA 54 and Gleason score (R-values were 0.724, 0.742, 0.768, 0.750, 0.784, P＜0.001). The expressionlevel of Apaf was positively correlated with Gleason score (rvalue was 0.549, 0.488, 0.425, 0.460, 0.562, P＜0.05). There was a negative correlation between TGF β expression and Gleason score (r-values were -0.674,-0.789,-0.856, -0.724, -0.764, P＜0.05). Conclusion The abnormal expression of ARA 54 and Apaf is related to the occurrence and development of prostate cancer. The low expression of ARA 54 and APAF can promote the proliferation and growth of prostate cancer cells. Therefore, it is of great significance to regulate the expression of Ara 54 and APAF in prostate cancer cells.