In Japanese lively conversation is described with the phrases “ikiga au” and “hanashiga hazumu”. “Ikiga au” literally translated means that interlocutors are synchronizing their breathing.“Hanashiga hazumu”literally means that the conversation bounces. The word synchronize refers to the perfection of timing of action and its maintenance. The word bounce refers to the rhythmic movement and its repetition. Both expressions are related to the rhythm of human action. In other words there is a sense of rhythm in lively conversation. As for school classes observers evaluate the rhythm of classroom conversation informally using such expressions as good rhythm or good flow and poor rhythm or poor flow. The classroom rhythm is generated by the series of rhythms of individual communicative acts between teacher and student and among students themselves. This research looks at communication not from the perspective of information exchange but from the standpoint of whether participants are trying to share the same rhythm. Rhythm does not simply occur as the by‑product of the communication of meanings. The author’ s view is that a certain rhythm and its repetition constitute a basis for communication.