Objective: Prostate cancer is typically mutifocal, and there has been no report about the exact number of prostatic carcinomas in each case. We have performed topographic analysis using three dimensional mapping technique. Method: We established data base including 904 cases of radical prostatectomy consisting of 2717 individual adenocarcinomas, and performed comprehensive pathologic analysis. Objective: TMPRSS2-ERG gene fusion is the most common genetic alternation in prostate cancer. It is associated with the expression of oncogene ERG protein. Recently, the immunohistochemical staining method that using anti-ERG antibody was verified strong correlation with ERG protein which is the product of genetic alteration. Aim of this study is to declare that the relationship between ERG expression and clinicopathological factor. Method: otal 307 cases of radical prostatectomy specimen were assessed. All cases were constructed tissue microarray and immunohistochemical staining was performed.