Many children in different communities are exposed to violence with different levels of economic, cultural and other social factors. One of the most important classes of children who are exposed to violence, are street children. Existence of street children should be seen as a result of modern urbanization. Disorganization in advancement and industrialization, makes entry of children entitled street children to urban environment. The phenomenon of street children has intensified at all levels in developing countries for reasons such as lack of growth and development balance in compared with developed countries. Street children are placed in different violence issues such as physical abuse, emotional and psychological violence and sexual violence. This type of violence are severely threatened street children's rights including the right to life, right to liberty and the right to human dignity. Login violence factors on street children can be divided into two categories; formal and informal violence factors. Formal factors are included legal entities that according to their legal duty are in associated with street children either directly or indirectly. Informal factors also include other individuals and social institutions such as family and friends of street children.