Objective: The purpose of this study was to explore the pathway from mothers overprotective parenting to their child s peer play interactions mediated by internalizing problems, that is, social immaturity and withdrawal. Methods: Surveys were conducted on mothers and teachers of 341 children aged three to five. SPSS 22.0 was used to analyze the data using descriptive statistics. Structural modeling analysis was also implemented to test theoretical model using AMOS 21.0. Results: Maternal overprotective parenting, which increased social immaturity of their child, indirectly reduced the child s positive interactions with peers during play. Mothers overprotection led to a higher level of withdrawal of their child while the effect of children s withdrawal on their peer play interaction was not significant. Because overactive parenting of mothers had no direct effect on peer play interaction, the complete mediation model representing a path from maternal overprotection to children s peer play interaction via their internalizing problems was partially supported. Conclusion/Implications: This study shows that overprotective mothers hinder their child to experience confident and mature manners, and eventually lead their child to be socially unskillful and incompetent. It was suggested to explore more individual characteristics of mothers and children to help overprotective mothers to take a step back.