Hadith is one source of Islamic law that has its privileges. This specialty lies in the narration system (sanad) implemented by hadith scholars to validate the validity (truth) of a hadith. The system was formulated by scholars by looking at the continuity of the sanad, the credibility of a narrator, and avoiding defects (syaz and 'illat). This paper aims to see how the urgency of the method of criticizing the credibility of a hadith narrator (Naqdus sanad) is to obtain an authentic hadith.