The purpose of this study was to examine the moderated mediation effect of gender on the influence of effortful control and teacher-child relationships on children’s social development. The participants were 163 children (aged 4-5 years) and their teachers. Mediation, moderation, and moderated mediation models were analyzed using SPSS 21.0 and PROCESS macro 3.5 programs. First, the teacher-child relationship mediated the relationship between children’s effortful control and social development. Second, the gender moderated the effects of the children’s effortful control on the teacher-child relationship. Finally, the indirect effect of teacher-child relationships through children’s effortful control on social development was moderated by gender. The indirect effect was significant, especially in boys. This study provides information about ways to guide a child’s social development according to their gender.