The problem of informal settlements is one of the problems that many developing countries suffer from, some of the developed countries also suffer from it, although the dimensions of the problem are different, and the informal settlements are a natural result to meet the human needs and to express their basic requirements when the state is unable to solve them. But it can not be separated from the economic and social conditions of a society. It is a direct expression of these conditions. Therefore, its treatment as a problem must be through the establishment of specific mechanisms to discuss the implementation and funding of such projects.  In recent decades, a more recent concept of "sustainability" has emerged. Sustainability as a concept has recently been called for and a major prelude to it as a kind of salvation from the environmental problems that have resulted in development processes in various fields, including urban development of all kinds , Which includes the development of informal settlements, where sustainability is one of the most important foundations and strategies for the development of informal settlements. The research aims to develop a set of mechanisms for the development of informal settlements according to the conditions of the urban, social and economic environment, As a key and complementary part of the mechanisms, to ensure that development projects are successful in achieving the desired urban sustainability when developing informal settlements.