The purpose of the study is to investigate young children’s verbal interaction in joint problem solving according to their age, gender and pairing conditions. A total of 120 4- and 5-year-old children were assigned to the matched dyad (pairing children with same level) or the unmatched dyad (pairing children with differing level) condition. Each dyad’s verbal interaction, while working with a block task collaboratively, were videotaped and then transcribed for analyses. As a result, the differences between the matched and the unmatched groups, boys and girls, and 4- and 5-year-old in total amount of verbal interaction are observed. Significant effect and interaction effect of gender for ‘task-oriented interaction’ and ‘affective support interaction’ were observed.