This article deals with the application of principles of Hadith in the prominent book of hadith known as “musnad al-bazār”. Imam al-bazār was a great scholar of his time in the field of hadith and its sciences, and he has addressed the issues related to the application of rules and principles of hadith in his academic work. Therefore, I have sought through this research to address several issues, such as introducing Imam al-bazār and his Musnad, and extracting the rules of the term that Imam Al-Bazzar has applied in his Musnad, such as talking about terms related to Jarḥ, taʿdīl and ʿilal etc, and I concluded from this research with a number of results. , the most important of which are: That Imam al-bazār mentioned more than one in his Musnad. Likewise, That Imam al-bazār was influenced by the term Imam al- tirmiḏī, and he did not deviate from his method except in a few hadiths. This research was organized into two chapters, a conclusion, and indexes. KEY WORDS: Imam al-bazār, Musnad, Principle of Hadith