This study investigated lexical diversity of L2 Korean learners’ writings. The study analyzed writings from 55 learners(American, Chinese, French and Japanese) in terms of the number of tokens, types, and D value, and compared them with the results in 남주연‧김영주(2014). The study found that (i) numbers of tokens and types and D value in writings increa1sed as the proficiency developed. (ii) nouns took the lead of lexical diversity increasement in both writing and speaking; however, verbs showed the diversity increasement at intermediate level writing and advanced level speaking. (iii) D value showed no big difference in both writing and speaking at high-beginner level. But more diverse vocabularies were used in writing at intermediate level, and in speaking at advanced level.