Child with three months begins socil react, while social experiences which recieve in first six years make foundations of all future relationships. Social development includes behaviors, alltitudes and affects which are reflected in childrens communication with adults and peers. Although the familly have the primary role in the overall development of the child and in a social one, the role of preschool teachers is not less important, it is multiple. The preschool teacher encorages child development, gives emocional support, leads and menages, mediates in a establishing peer relationships. Familly, peers and preschool teachers includes different systems that complement each other, influence to each other and together contibute and encourage development of the childs socil competence (Vrbančić, 2016). In the educational work of the kindergarten, preschool teacher shoud pay particular attention to the processes of learning social behaviour, he shoud be a role model himself, and the goals od educational work must include encouraging positive behaviour of children based on establishing quality interactions, mutual respect and??. Althougt the effects of preschool teachers on the social development of children havent been prove, experience shows that they have an important role in promoting social development (Katz and McClellan, 2005). To encourage childrens social development, the reschool teacher must know the characteristics of child development, respect the individual needs of children, emotions, try to understand their thinking and behaviours and accordingly know how to apply different ways and strategies in educational work. Socially competent are children who start and archieve satisfaying interactions and activities with adults and peers and in that way improve and develop their own personal competence. This paper consider the ways how to preschool teacher can contibute to child social development, bring out some principles that help in making everyday decisions and strategies that promote social development of the children and develop childrens social competence.