This study investigated how Korean high school students use English connectives in argumentative writing. The participants were 71 high school second year students. Analysis of data focused on three aspects of connective use: 1) the frequency and kinds of connectives used, 2) commonly used words in each category of connectives, and 3) frequently used positions of connectives. Considering the possible effect of topical knowledge and general English ability, the analysis included the comparison between two topic groups and between two language ability groups. The results showed there was a high similarity between different topic groups and ability groups in the use of connectives, but a significant difference was also found in some limited features. Based on the results, the study concludes that Korean high school students, regardless of the writing topic and language ability, share common features in the use of English connectives. Some suggestions are made for further research and writing instruction.