The present study investigates the various editions of the earliest Sino-Mongol glossary known as the Chih-yüan i-yü or Meng-ku i-yü which is contained in the early-Yüan encyclopedia Shih-lin kuang-chiby Ch'en Yüan-ching. There are numerous editions of this popular encyclopedia dating from the Yüan and Ming periods, as well as an important Japanese edition of 1699 reproducing the Chinese edition of 1325/26 which is no longer extant. There are considerable variations in the Chinese phonetic transcriptions of the Mongol words in the glossary, mostly due, however, to scribal errors. The Chih-yüan i-yü/Meng-ku i-yüwas the subject of two detailed linguistic investigations by L. Ligeti and G. Kara in 1990 (AOH44, 3). The present study is meant to complement and supplement their investigations by providing further information on the textual history of the glossary. At the same time the author offers possible explanations for a dozen or so terms that could not be satisfactorily interpreted by previous researchers.