After an overview of the concept of urbanization in Southeast Asian countries, including the stage of over-urbanization from the 1950s to the 1970s, and the stage of global urbanization from the mid-1970s onward, I discussed the urbanization of Myanmar, especially the urbanization process of the capital Yangon, and various aspects of Yangon's over-urbanization as a case study of "Over-urbanization in the Third Country".