This thesis looks into the Fighi methodology of Abdullah bin Abdul Aziz al Basri, one of the jurisprudent scholars of the Islamic Ummah in the second century A.H.. The thesis will use his scattered opinions in the writings of Abi Ghanim al Khurasani and is divided into an introduction, four chapters, and a conclusion. The Introduction explores the subject problems discussed by the thesis, its limitations, reason of choice of subject, literature, importance, goals, and the methodology of research and writing. Chapter One: explores the life of the jurisprudent scholar Abdullah bin Abdul Aziz from two angles: the first, his personal life, explores his genealogy, date of birth, ethics, and date of death. The second, his intellectual life, explores the influencing factors of his scholarly personality, his teachers, students, contemporaries, his status as a scholar and the Ibadhi's standpoint towards him. Chapter Two: discusses the standpoint of Ibn Abdul Aziz with regard to the two types of Islamic legal evidences, primary and secondary, and his way of using them with some examples and application. The chapter also discusses his standpoint with regard to legal maxims and principles, mentioning some examples of their usage from his discourse and legal opinions. Chapter Three: talks about his views of the ijtihad and taqleed, his methodology of discussing fiqhi issues and his fiqhi presence in the Ibadhi books. Chapter Four: includes models of the fighi issues in which he had a different opinion than most of the Ibadhi jurisprudent scholars. This chapter has a comparative exploration of the issue of the punishment of the female apostate according to different Islamic schools. The conclusion: includes the most important results of the study. The thesis concludes with providing some recommendations.