This study explores useful ways of using an instant messenger in a peer-tutoring environment when two students exchange their mother languages. Seven learners of Korean and seven Korean students learning English were paired randomly to conduct language exchange via an instant messenger, KakaoTalk. The pairs (five of male and female pair and two of same gender pair) were engaged in a one-hour session once a week for ten weeks, half an hour in Korean and half an hour in English. The meeting aimed to improve partner's pronunciation, vocabulary and understanding of the cultures. The results of the exchange activities showed the positive impacts of language exchange for students.