This paper proposes a methodological framework, contrastive conversation analysis, to analyze some of the listener back-channel expressions in Japanese and American-English conversations. The examined expressions are limited to uh-huh's and the like, brief comments, punctuated head movements and laughter. It is shown that listener's response such as brief comments and head movements occur far more frequently in Japanese casual conversation and that relevant contexts for listener back-channels differ significantly in each speech community. Grammatical completion, sentence-final particles and speaker's vertical head movement provide the relevant context in Japanese, whereas grammatical completion provides the single most significant context in English. The results of the contrastive study are evaluated and assessed in light of the potential problems of CCA, with the issue of `equivalence' being the most serious and problematic. Additionally, as a step beyond CCA, four intercultural conversations by American and Japanese speakers are examined.