Japanese and Korean are typologically similar languages, and a linguistic phenomenon in the former often has a counterpart in the latter. The papers in this volume are from the twenty-first Japanese/Korean Linguistics Conference, which was held at the Seoul National University in October 2011. The collections in this volume include essays on the phonology, morphology, syntax, semantics, historical linguistics, discourse analysis, prosody, and psycholinguistics of both languages. Such comparative studies deepen our understanding of both languages and will be a useful reference for students and scholars in either field.