This study analyzed Korean language learners’ writing texts using T-unit analysis measure that was adapted to Korean syntactic structure in order to find out adequate measures for learners’ syntactic proficiency. The result appeared 12 of 18 measures to be increased with the level and it means those might represent the syntactic proficiency of learners’ writing texts. Among those, average number of words per sentence, average number of clauses per sentence, the proportion of error-free clauses to clauses might be the best measures for fluency, complexity, accuracy of syntactic proficiency. (Yonsei University)