Ryu Jisu·Jeon Moongee This study aims to analyze the text complexity of elementary school Korean textbooks of grades 1-6 by employing Auto-Kohesion, a Korean analysis tool, based on many linguistic and psycholinguistic measures. The results showed that text complexity gradually increased across grades by the surface-level measures (e.g., the number of sentences); however, it was not reflected by most of the other measures (i.e., cohe- sion measures, lexical diversity, connectives, pronouns, word frequency, modifiers). The results have pedagogical implications for the develop- ment of Korean textbooks, which aims to maximize the learning gains of Korean language learners.