The objectives of this paper are explicitly stated as the following. First, it aims to establish the term ‘complex discourse markers’ to describe combinations of discourse markers frequently used in spoken language. Second, it seeks to extract combinations of discourse markers from a large-scale corpus to provide a comprehensive overview of all items classified as complex discourse markers. Third, it intends to classify the types of composite discourse markers to establish its systematic framework. Initially, this paper defines complex discourse markers as “a speaker’s utterance strategy used to effectively convey intentions in immediate dialogue, where two or more different discourse markers are tightly combined within a single intonation unit and their combination is typified as a usage pattern.” Subsequently, rationale behind this definition based on prosodic, morphological, and functional characteristics is examined. In immediate dialogues, intonation units hold significant positions where different discourse markers are tightly combined and patterned, serving as a cohesive functional strategy for speakers, and are examined as a single kind of unit. In this paper, a total of 247 items were selected. These items were classified according to their formal characteristics and were categorized according to preceding factors to systematize types of discourse markers. This paper challenges previous studies that overlooked the combinatory nature of discourse markers and suggests a multifunctional classification of their functions. It raises issues concerning misconceptions about the functions of discourse markers and the overlooked phenomenon of their frequent combinatory usage by speakers when analyzed without considering their combinations into cohesive units. From a functional linguistics perspective, frequent combinations of linguistic components are seen as motivated by functional reasons. It is reviewed as originating from the speaker’s strong utterance strategy. Therefore, it is concluded that the combination of discourse markers should be designated as “complex discourse markers.” This topic and methodology are considered valid for research, given that while it has been relatively well-studied in other languages such as English, it remains unexplored in Korean. Future tasks include addressing the functional analysis of complex discourse markers, an area not fully elucidated in this paper.