Recent studies in conversational interaction across speech commuities have revealed that not only grammar proper, but also interactive strategies at a time of face-to-face encounter differ from language to language. Although in the past, conversation analysts have pointed out differences in some aspects of interactive competence, often such studies have been plagued by their ad-hoc nature of data, anecdotal accounts and casually defined contrastive context in which the analysis is made. In this study we attempt to understand one aspect of interactive competence, i.e., conversation management through back-channel strategies in a specific contrastive context of casual conversation in Japan and the United States. The methodology adopted here is what we may call “contrastive conversation analysis” as opposed to Hartman’s (1980) “contrastive textology” in which primarily written text — what he calls “parallel text”— is analyzed. Note that although so-called contrastive analysis has been under attack over the last two decades — primarily because of its failure to meet unrealizable expectation i.e., prediction of learners’ errors in its own right, widely held among applied linguists especially in the United States—the term contrastive analysis used herein is broader in its application and does not necessarily predict actual learners’ errors. Based on this framework, this study investigates “back-channel” expressions, such as uh-huh’s and brief comments received by the person who has the turn without relinquishing the turn as characterized first by Yngve (1971).