Study problem. The group of individuals with severe and multiple disorders included children who had moderate, severe or profound mental retardation in combination with other developmental disorders. Studying the adapted basic general educational program by students implies that they achieve two types of results: personal and subjective, which, in turn, requires learning the norms of social behavior in addition to subject components within the educational environment. This leads to an incomplete understanding by parents of the possibilities of teaching a child socially appropriate behavior, which, in turn, reduces the adaptation abilities of children in the society.The relevance of the study is determined by the growing interest of the society in teaching younger schoolchildren with severe multiple developmental disorders socially acceptable skills, developing a psychological line of social behavior as an active adaptation to the conditions of social environment.The purpose of the study is theoretical substantiation and scientific and methodological development of conditions for the formation of social behavior in younger schoolchildren with SMDD.The study involved 35 younger schoolchildren with severe multiple developmental disorders. It has been experimentally proved that students with SMDD are characterized by low (52%) and critically low (25%) competence in social behavior. A qualitative analysis of the actions of students in life situations shows that they better comprehend tasks, which are simple every day and communicative actions. Students are least competent in ways of acting in situations that require seeking help from adults. The results of the study can be used in: 1) the development of scientific and methodological guidelines for teachers for planning and implementation of a work system on the formation of social behavior 2) the preparation of practical materials for parents on the formation of socially acceptable behavior (in the family, in public places, in transport). 3) the implementation of study materials in the course of teachers’ practical training.

children with severe multiple disorders, mental retardation, social behavior, educational standard, non-school activities.