Abstract: The subject of the research is the analysis of the conjunctive method of connecting words and sentences in the Buryat language compared to the Bargut language. The object of the research is the functions of conjunctions as the main grammar method of connecting words in the Buryat and Bargut languages. The aim of the research is to provide a system description and structure-functino analysis of Buryat and Bargut conjunctions. The authors of the article focus on correspondences, common features and differences of Buryat and Bargut conjunctions represented by two groups of conjunctions: composing and subordinating conjunctions. In their research the authors have applied the descriptive method that implies observation and generalisation as well as the continuous sampling method, comparative method, field processing method and component analysis that demonstrates both general development patterns and specific features of the language. The novelty of the research is caused by the fact that Mongolian studies do not particularize conjunctions of sister languages like Buryat and Bargut from the point of view of their similarities and differences. The results of the research can be used to compare historical grammar of Mongolian languages and study the issues of grammar and vocabulary of the modern Buryat and Bargut languages.