This study analyzes oral presentation given by intermediate Korean language learners to examine discourse cohesion shown upon using cohesive device. It focuses on the use of conjunctive adverb and connective ending, both as a cohesive device, in terms of their application and appropriacy, in particular, based on the variable L1 of learners. The application in their use is measured with quantitative analysis and the appropriacy with qualitative analysis. The analysis is confined to the use of conjunctive adverb and connective ending among other cohesive devices of discourse, resulting in varied application of conjunctive adverb according to the variable L1 and its higher error rate than connective ending in their use. On the contrary, it does not show any significant difference in using connective ending according to the variable L1 and relatively lower error rate than that of the conjunctive adverb. It is noteworthy that a Thai student as KFL and a Chinese student as KSL comparatively underuse conjunctive adverb. It is very critical to effectively use cohesive device including conjunctive adverb and connective ending for logical flow of oral presentation because the oral presentation is unidirectional form of discourse and should deliver a speaker`s discourse to audience even when shared knowledge or a schema of discourse is not given prior to the presentation. The use of cohesive device in oral presentation helps logical connection of discourse, thus reinforcing discourse cohesion and, for better understanding, enabling a listener to make logical inference about context of the discourse. In this regard, it is required to improve teaching and learning methods in accordance with the variable L1-based, different type of learners.