Drawing upon the recent attention to the usefulness of contrastive interlanguae analysis of L2writing, the current research explores the written language characteristics of the Korean learners of English at the college level. Specifically, a collection of 111 Korean learners’ argumentative writings is compiled into a learner corpus and the corpus was statistically (using keyword analysis) compared with a native speakers’ argumentative writing corpus and a general English reference corpus. The preliminary descriptive analysis found that the Korean learners frequently use the first pronouns such as I and we, which is one of the contrasting characteristics of the native speakers’ argumentative writing and general English. The keyword analysis found that the Korean learners overuse and underuse certain words: think and thing are overused; the and of are underused. The negative keywords, such as the and of and the frequency of their combined structures were also examined. The results suggest that the Korean learners may have their preferred word usages, which may reflect the lack of productive vocabulary knowledge,especially collocation structures. Based on the findings of the research, pedagogical implications from the result are also discussed.