Conducting comparative studies in education has a long-lasting background in many societies; however, in the last few decades, the tremendous growth of Information and Communication Technology alongside researchers’ interest in broadening their knowledge of the role of education systems in socio-economic development of countries have yielded a growth in comparative research in all humanities disciplines. Hence, awareness of the theories, methods as well as rules applied in comparative studies is of vital importance. Nevertheless, comparative educational studies in Iran have been confined to a superficial understanding of the similarities and differences between education systems. Therefore, the present article aims at introducing new methods of research in comparative educational studies. The paper starts with an introduction to the comparative studies. Next, the characteristics of comparative research are explained. The main part of the paper elaborates on John Stuart Mill comparative research Method of Agreement, Method of Difference, and Boolean Algebra Method, respectively. The paper would end with a brief comparison of these methods and a conclusion.