This study aims to study and analyze the hadiths of Jamie Ibn Ja`far', the most important book of the early Ibadhi scholars, then compare themes with other sources of hadith; to shed light on the first stages in how the Ibadis dealt with the Prophet's Sunnah in terms of narration and body. The research questions were:  What is the importance of the Sunnah according to Ibn Ja`far?  What are the aspects of inference for the Sunnah in Jamie Ibn Ja`far'?  What are the similarities and differences between the hadiths of Ibn Ja`far' and other hadith books? In order to answer these questions, the researcher first extrapolated all the hadiths mentioned in the Jamie Ibn Ja`far and distinguished them from the hadiths that added later to the book, then compared them with their occurrence in the other books of the Hadith and analyzed their terms. Among the most prominent findings of the study: - The Jamie Ibn Jaafar has a great position among the Omanis. - The Prophet's Sunnah is the second source of legislation for Ibn Jaafar after the Holy Qur'an. - The researcher found 149 hadiths in Jamie Ibn Jaafar. - The number of hadiths of Rabi` that match either verbal or meaning with the hadiths of Jamie Ibn Jaafar is 25 hadiths. - The researcher found 11 hadith sources contemporary or previous by Ibn Jaafar that were unique to citing hadiths mentioned by Ibn Ja`far in his book. - The researcher found 11 hadith sources written after the era of Ibn Ja`far that were unique to citing hadiths mentioned by Ibn Ja`far in his book.