The purpose of this study is to analyze English writings collected from 6th grade students in a Korean elementary school using Coh-Metrix. Coh-Metrix is a computer tool that has been widely used to study English corpus with various psycholinguistic measures. A total of 176 English writing samples were collected from Korean elementary school 6th grade students. Specifically, the English writing corpus consisted of three groups classified by the 6th grade students’ English proficiency performance assessment tests. The findings of our study indicated that there were statistically significant differences among the three groups for number of words, number of sentences, Flesch Reading Ease score, Flesch-Kincaid Grade Level score, additive connective, pronoun ratio, and the third person pronoun measures. On the other hand, there were not statistically significant differences among the groups for mean sentence length, word frequency, syntactic complexity, type-token ratio, co-referential cohesion, semantic cohesion, casual connective, temporal connective, the first person pronoun, the second person pronoun, and word information measures. Implications for English writing education for elementary school students are discussed.