The purpose of this study is to examine the effect of mother’s language control style on infant’s emotional regulation ability and peer play interaction. The subjects of this study were 250 children aged 4-5 who were hospitalized in G city and their mothers. For the collected data, correlation analysis and step-by-step regression analysis were performed using the SPSS 24.0 program. As a result of the study, First, it was found that imperative control, a sub-factor of mother’s language control type, had a negative correlation with emotional regulation ability. Command control and positional control were found to have a positive relationship with play interference, which is a sub-factor of peer interaction. Second, it was found that among the types of mother’s language control, imperative control had a negative effect on emotional regulation ability and positive play interaction, and positional control had a significant effect on emotional regulation ability and positive play interaction. The results of this study can be used as basic data for parent education conducted in the field of early childhood education by knowing the importance of mother’s language control type.