In this book, Ákos Bertalan Apatóczky offers a complete reconstruction of the Chinese-Mongol vocabulary of the 17th century comprehensive Chinese military work called Lulongsai lüe (盧龍塞略, LLSL), a document of key importance containing one of the last Sino-Mongol glossaries without proper critical reconstruction until now. The work has resulted in a clarification of the earlier sources the compilers of LLSL used in the bilingual part. The author argues that contrary to what scholars have thought of it until now, the linguistic corpus of the glossary is not homogeneous and does not represent a single linguistic status; it does, however, shed some light on chronological and philological questions concerning the earlier works incorporated in it.