The current study was conducted for elementary school 6th graders, aimed at clarifying the consensus formation process based on an analysis of their utterances/descriptions in various “Discussion Activities”. The utterance contents revealed that more than half of the students who participated in the “Discussion Activity” reached a consensus formation after repeated disconfirmation type and sharing type utterances, which are interactive dialogues with others. Meanwhile, the description contents revealed that most of the students who submitted to self-searching after the “Discussion Activity” followed a sharing process based on metacognitive activity (monitoring, verification, adjusting).