Abstract
The science of Jarh wa Ta'deel (Recommending or not recommending Narrators) is regarded as a cautious because of its numeral branches, issues and its influence on accepting or rejecting Traditions. Hadith Scholars have made good efforts in this sense, they have collected all about narrators, which show their attitude regarding relation (Riwayah). This article focusses on priority terms which were used by scholars of Jarh and Ta'deel by which they distinguished between reliable narrators in different sides, also between weak narrators, and to put some traditions in advance. The article also discusses some attentions to certain issues, which are needed to Hadith Scholars in searching Hadiths, or the biography of Narrators, the judgment of their traditions, when it is difficult to judge the narrator and his narration because of neglecting such issues and their applications.