The purpose of this study is to determine the effects of CMC-based English learning. In this study, CMC components were found to provide circumstances of facilitating interactions between student-student and student-student-teacher, which enabled students to accomplish language learning tasks. Findings of this study are as follows: First, CMC based language learning experience helps students have positive attitudes toward their English language learning. Second, student-student-instructor interaction group outperformed other groups in academic achievement and class activity participation. Third, cooperative learning groups more actively participated in the class activity than the individual learning group resulting in better academic performances. These findings supported the fact that cooperative learning with CMC components are useful in bringing more class participation and positive attitude that were believed to foster language learning than other groups in traditional language learning environments. This study suggests that the instructor needs to use instructional design strategies helpful to facilitate active interactions between instructors and students in order to achieve better effectiveness of English learning in a CMC based learning environment.