Abstract: Suburbanization or as it is called today, informal settlement, is the consequence of rapid urbanization and transfer to socioeconomic paradigm of industrialization. Swift and unbalanced physical development of cities has been followed by undesirable economic, social and skeletal consequences. One of the effects and consequences of inharmonious urban physical development includes suburbanization and informal settlement. Nowadays, thousand million people of the world especially in developing countries live in unauthorized and disturb residences and under poor economic, social and environmental conditions. According to the report released by the UN, informal settlements (suburbanization) have been identified as the main challenge of the third millennium. On the whole, in the world one out of every six individuals lives in informal settlements. About 2 billion persons of the urban population of the world will live in such residences until the year 2030. In this research, first, the concept of informal settlement and different theories about the subject of research has been studied. Later, the corresponding problems with informal settlements and characteristics of these residences will be explained in detail. At the end, the approaches for intervention with informal settlements are studied from the beginning through the present time. The main goal of this research is to describe the respective problems with this type of residences and recognition of the intervention approaches.