The authors attempted to choose what has the best reproducibility and predictability for prognosis of the prostatic adenocarcinoma among four most widely used gradings methods; the Gleason's Mostofi's, Bocking and MD Anderson hospital systems. According to these gradings systems, each of two pathologists made histologic gradings of 40 consecutive prostatic adenocarcinomas which had been diagnosed with the surgically resected specimens. Correlation between the histological grades and the clinical stages was studied and a comparison was made among each system. For the comparison, the Gleason's and MDAH systems were revised as 3 grades and adjusted to the other gradings systems. In this study, MDAH grading system yielded the highest reproducibility as represented by 90% agreement, as compared with the other systems which showed 82.5~87.5% agreement. By the Gleason's, Mostofi's and Bocking's systems, 46.2%, 23.1% and 46.2% of grade 3 tumors respectively fell under the clinical stage A. On the contrary, there were no cases of grade 3 in stage A and no cases of grade 1 in stage D, by MDAH gradings system. These results suggest that MDAH gradings system is superior to the other systems in reproducibility and for predicting the biological behavior.