Considering the recent issue for the importance of vocabulary in the field of Korean as a foreign language. Teaching vocabulary intentionally and systematically should be accomplished to improve learner’s lexical competence. In order to accomplish this, it is necessary to understand learner’s cognitive process of learners’ acquisition of vocabulary and to clarify the process that how lexical competence affects the leaner’s language performance including measurement for this process. Especially post-intermediate learners of Korean feel little pushed when using grammatical elements, and at the same time they tend to have difficulty with their poor lexical competence. For beginners, because beginners have no alternative but to stick to basic grammatical elements which is necessary for simple communication, the range of using vocabulary is limited. However, it is not so difficult for post intermediate learners to use minimal grammatical knowledge for communication, which means that they have more chance to concentrate on vocabulary and it could help them get better communicative competence. It can be sophisticating to choose the method for teaching and learning vocabulary, which can be a wide application for various kinds of learners. I hope this study can contribute to improving learner’s competence vocabulary memorization in teaching and learning for intermediate and advanced learners of Korean vocabulary emphasizing the semantic approach. (Hankuk University of foreign studies)