Background and Purpose: Man is a social being. The social aspect of child development shapes the basis of his/her life. Social life demands mental readiness, social skills, self-confidence, and social adjustment. This study aimed to determine the development of social relationships in children aged 4 to 6 in the kindergartens of Qom province, based on the demographic status of their families. Method: To carry out this causal-comparative study, 300 children aged 4 to 6 (150 boys and 150 girls) were selected by multi-stage cluster sampling from ten kindergartens of Qom province in 2016. Development of social relationships in these children was determined based on the subscale of the social relationship in Newsha Cognitive, Social Communication and Motor Development Scale for Persian Speaking Children (Jafari et al., 2009) and Researcher-made Demographic Test. Descriptive statistical techniques, Kruskal-Wallis test, and Mann-Whitney U-were used to analyze the data. Results: Results showed that development of social relationships in these children improved with age. The demographic variables, including the paternal level of education (p <0.714), maternal level of education (p<0.574), paternal income (p <0.796), maternal income (p <0.479), housing status of the family (p<0.330), history of parental death or divorce or death of a loved one (p <0.433), history of psychiatric problems in siblings (p<0.758), being right-handed or left-handed (P <0.351), being monolingual or bilingual (p <0.907) had no effect on the development of social relationships in these children. Conclusion: In general, results of this study showed that based on developmental theories like social development theory and social learning theory, child's social relationships improves with age. Also, noneffectiveness of family demographic factors on the child's social relationships indicates the importance of social learning theory and it shows that children are affected by socialization factors outside the family.