This study aimed to examine the influence of parent–children interaction, peer-to-children nteraction, and children’s vocabulary on their intelligence. Participants included 313 children aged 60 to 67 months. Data were extracted from the 6th year (2013 : 2nd year in-depth survey) of the K-WPPSI and the 6thyear (2013) of the KICCE. The collected data were analyzed using the Pearson correlation coefficient and stepwise multiple regression analysis. The SPSS program was used to perform all analyses. Findings revealed a significant static correlation between parent–children interaction, peer–children interaction, and children’s vocabulary. The regression analysis on the overall intelligence of children showed that their vocabulary, surprise interactions, parent–children interaction, and vocabulary, which are sub-factors of peer–children interaction, had significant explanatory power. The present results are meaningful as basic data on early childhood intelligence, derived from Korean panel data on children.