Lee, Kil-yong․Son, Min-su. 2012. The development process of Communication Strategies in Japanese by korean learners. The Sociolinguistic Journal of Korea 20(1). pp. 161-176. In this study, focused on the first language-based strategies and the target language-based strategies about the development of communication strategies in Japanese by three korean learners were investigated. The results are summarized as follows. First, as target language proficiency increases, the frequency of the first language-based strategies and the target language-based strategies generally tended to decrease. However, the case of the beginning level learner, as learning progresses, the frequency of the target language-based strategies increased. Second, as target language proficiency increases, the frequency of the first language-based strategies generally tended to decrease. However, as chaotic-period of the first language and the target language, the intermediate-level learners increased the frequency of the first language based-strategies. Third, as target language proficiency increases, the frequency of problem-solving strategy of the sentence unit increased than problem-solving strategy of unit vocabulary. This study will have important implications to say that by analyzing the longitudinal data of three cross-cutting learners of differing proficiency target language, we attempted to elucidate the developmental processes of communication strategies.