This article is dedicated to the analysis of techniques of external enrichment of terminology of the Vietnamese language. An attempt is made to examine the phenomenon of borrowing of foreign words in military terminology of the modern Vietnamese language. The author explores the factors of borrowing, carries out classification by origin and source of borrowing. The relevance of this work is defined by the need to systematize knowledge on the foreign borrowings in military terminology of Vietnamese language at the current stage of its development, rapid advancement of military science, new technologies, integration of Vietnam into the global community, and, thus, the emergence of vast foreign lexicon from Western languages, including in terminology. The novelty consists in systematization, generalization, and analysis of the methods of foreign borrowing in Vietnamese language and sectoral terminologies, particularly in military terminology. The conclusion is made that military terminology of Vietnamese language contains 80% of borrowings from foreign languages. According to the source of borrowing, foreign words are divided into two groups: of Sino origin (Hán Việt), and of Indo-European origin. The basis of borrowings is comprised of the terms of Hán Việt origin, which in have assimilated and currently are fully functional units of Vietnamese language. At the present stage, most of the words are borrowed from the English language; the majority of loanwords from European languages in Vietnamese language are attributes to semantic (word-forming and semantic calques). This method of borrowing often makes the terms too complex, difficult to remember and use. Borrowings from European languages, which currently infiltrate into Vietnamese language without changing their graphic form, are pronounced in accordance with the phonetic norms of Vietnamese language.