Third part of a 4 Volume series "Economic Doctrines of Islam" by the economist Mr. Afzal-ur-Rahman.The author has discussed in detail all the aspects of the Economics of the present age in the light of Islamic teachings. He has also discussed the prevalent Economic systems of the modern world, analysed them to the Economic system of Islam.Third volume explains the modern theories of interest and presents the Islamic Theory of Zero Rate of interest. It also discusses the system of Zakat and the Law of Inheritance and their place in the Islamic System.