This study aim is to follow and put the spotlight on the political situations in Dhofar region under the reign of Al-Kathiri state from( 9th century AH / 1519 century AD to the beginning of 12h century AH/ 18th century AD ).The study will focus on the important internal political eventsin Dhofar region, the policies that were implemented by Al Kathir sultans and how it affected Dhofar and also to provide the external political events between Al-Kathiri Sultanate and other countries of that time. The researcher of this study relied in his research on the primary important references on that era and some of the new studies that discussed the topic of this research. The study followed the historical method that relies on description, analyzing historical accounts and comparing these accounts while reviewing different opinions around these points that they discussed. This study contains an introduction, preliminaries to the study, three chapters and ends with a conclusion chapter. The introduction chapter includes the objectives of the study, why it is important and old studies that discussed Dhofar history during first Al-Kathiri Sultanate era. The preliminaries to the study include the geographical location of Dhofar and its important characteristics, the naming of Dhofar and its historical significance and a historical background of Dhofar till the Rasulid dynasty. The first chapter is about Al-Kathir lineage, their origin, their appearance on the political scenes and the situation in Dhofar at the end of Rasulid dynasty till the takeover of Dhofar by Al-Kathiri state. While the second chapter is about the political situations in Dhofar under the reign of Al-Kathir from its beginning until the Zaidi intervention in Dhofar. The third chapter studies the relationship between the Kathiri state and the Zaidi and its effect on Dhofar. This study concluded some results like that Dhofar region continued to be under first Al-Kasthiri state reign till the beginning of12" century AH /18th century for three centuries. The study also showed that Dhofar went under Al-Kathiri reign through many internal political events which resulted from the policies of the sultans .Also the region has witness eddirect impacts resulting from the external relationships of Al Kathiri state ranging from friendly relations, based on mutual understanding and cooperation, and the relations of aggression, based on military confrontation and conflict, that had some rolein the weakness of Al-Kathiri state, and event uallyits collapse.