In this article, Yaqub Abu Yusuf, one of the greatest scholars in the Islamic world, made a great contribution to the development of science and culture through his socio-philosophical views, based on the analysis of a large number of taxes in practice in the caliphate, the book "Kitab ul-Kharaj" written about the Islamic tax system, the country's economic its role in life has been studied. We formed new knowledge based on extensive and thorough study of Yaqub Abu Yusuf's personality and his work "Kitab ul-Kharaj", in particular his great efforts in the direction of national peace, material and spiritual life of citizens. Especially Abu Yusuf's development of the tax system, the description of tax types based on one by one accurate calculations, greatly helped the Islamic countries in the subsequent management system. We can see Islamic tax system in practice in some modern Islamic countries as well.