This study analyses the discourse marker ‘Geunyang‘, which is used frequently in spoken discourse for providing a basic data for the Korean Language Teaching with a focus on communication. Through the discourse analysis, the study claims ‘Geunyang‘ as a discourse marker, and determines the meanings and the functions used in different situations. In order to overcome the disadvantages of semi-spoken corpus and spoken corpus, the research incluses both of the 21st century Sejong corpus [2009] and the drama script corpus. The background of the study, Gramaticalitation and Discourse Analysis, is discussed in Chapter 2. Considering the previous studies, the paper clarifies the concepts including the terms, definitions, characteristics, features, as well as the classification of the discourse marker. Moreover, the critical points are figured out in the advanced study to complete the paper. Chapter Ⅲ proposes the idea of ‘Geunyang‘ as a discourse marker based on its characteristics. Furthermore, in the Chapter IV the uses as adverbial and discourse marker are separated. Additionally, the characteristics of ‘Geunyang‘ as a discourse marker in feature, morphology, rhythm, and syntax are examined. Chapter Ⅳ analyses the function of ‘Geunyang‘ concretely. As a result, ‘Geunyang‘ has a function that supports the cohesion in discourse. The cohesion includes not only the speaker and topic but also the speaker and listener, topic and topic. Besides that, ‘Geunyang‘ has the function of modality expressing the speaker‘s thought. In addition, the suitability of ‘Geunyang’ as a discourse marker through the Grammaticalization and the needed process is argued. Also the co-occurrence of ‘Geunyang‘ as well as other often used discourse markers is considered. Chapter Ⅴ presents a summary of the results, significance and the limitations of this study.