From a social-interactionist's view of language learning, "reflective conversation" via CMC, particularly through the asynchronous mode, has been advocated (Lamy & Goodfellow, 1999). It emphasizes learning through reflection on experience and through the exchange of thoughts with others. Guided by this pedagogical model, asynchronous discussion was implemented in an EFL content-based course taught twice in 2003 and 2004 that integrated learners' language learning experience with language learning theories. The study investigated the effectiveness of learning both content and language in this experience-based language learning course through asynchronous discussion and also examined the reflectiveness and interactivity of the participants' online exchanges. The results showed that most of the participants held a highly positive view on this CMC learning activity. Moreover, their reflectiveness in asynchronous discussions was found to be affected more by peer interaction than by the instructor's participation. Of particular interest is that the differences found among discussion groups revealed that the higher participation level the students had, the more positive view they held. This can be well supported by Wenger's social theory of learning emphasizing the importance of active participation.