This study aimed to widely point and clarify this Imammh which although last for a short time, it changed the history of Yaman for a long period. This was caused by the Ibadi ideology that was spread all over the Yaman. It became the belief of Yamanies in general and Hadhramot inhabitance precisely at that period. In this study the researcher has used the deductive method which relied on studying and analyzing historical novels and trying to make them consistence. This study included introduction and three chapters. The introduction clarified the political and economical situation in Yaman and Hijaz during the Amawi government. It focused more on the period when khalifa Marwan Ibn Muhammad ( the last Amawi khalifa) was ruling the islamic empire. However, in chapter one the researcher wrote about the start of Ibadi Imammh in Hadhramot and the circumstances that lead to that start, as well as the Ibadi power in fully controlling all of Yaman and getting rid of the Amawi Wali. Moreover, he mentioned all the battles that the Ibadies fought to rule Yaman. In the second chapter, the researcher clarified the wide-spread of Imammh in Hijaz, its victory in controlling Maca and Madina Munwwara, and getting rid of Wali of Maca Abdel Wahid Ibn Sulayman. However the researcher was mostly concerned of the Imammh-braking dawn by the army that was send by Marwan Ibn Muhammad. His army was able to win all of the battles one after another against the Ibadi army. After that the researcher explained all the details till the assassination of the Imamm Abdullah Ibn Yahya Al-Kindi. Moreover, he clarified the continuous existence of the Ibadi in Hadhramot despite its collapse in Hijaz. Finally in the conclusion, the researcher highlighted the main results he ended to through the whole story of Ibadi Imammh: 1) The Imammh was the greatest aim for all of the Ibadh A'emma and leaders. 2) They prepared for its existence for along period of time through establishing a wide-ground in Yaman. 3) The Ibadi existence continued in this part even after the Imammh was destroyed. 4) Too many of Omanis, as well as, Ibadies from different backgrounds, participated in this Imammh and were the corn of the first Ibadi Imammh in Oman.