The monograph focuses on the life and work of Yakub Abu Yusuf ibn Ibrahim al-Kufi, who is known as Abu Yusuf in the Islamic world, the services of the thinker in the spread of Hanafiism, the work done by the thinker, especially the issues of the tax system in the early Islamic period. Information about socio-economic life, religious-philosophical and Islamic tax system described in Abu Yusuf's "Kitab al-kharaj" was analyzed. Also, the socio-political situation in the Muslim East in the 8th - 9th centuries, cultural-educational relations during the first Abbasid caliphate, the economic-philosophical aspects of Abu Yusuf's views on people's well-being and the idea of social justice are shown.The monograph is intended for researchers and a wide readership interested in the history of philosophy, religious studies, source studies, political science, and the history of Islamic finance.