Theories of modernization, old and new Pioter Sztompka /Gh.R. Arjomandi Theories of modernization and convergence are the product of the post Second World War era. Both have been formulated in response to the new emerging division of human society into three distinct ‘Worlds’: the First World of the developed industrial society; the Second World of the ‘socialist’ societies Payke Noor, 1/14 and the Third World of the postcolonial societies of the South and East. Classical theories of modernization focus on the contrast between the First and the Third Worlds, whereas the theories of convergence, as well as recently emerging theories of post-communist transition, take the cleavage between the First and the Second Worlds as their main theme.The conconcept of modernization, the mechanism of modernization, the critique of the idea of modernization and a brief account of Neomodernization and Neo-convergence theory are the main axes of this subject.