The article deals with the use of comparison in scientifi c works on pedagogy and theory of teaching Russian as a foreign language. The research methods are the generalization and systematization of the data refl ected in the scientifi c literature. The authors view comparison as a central research procedure in comparative pedagogy. They describe two general rules of comparison, as well as the operations that are carried out during the comparative study. As an example, a description of the comparison of Russian and Chinese curricula in the Russian language for Chinese students, is given. The methodological signifi cance of this research procedure is emphasized. Comparison is seen as the core for the theory of optimization of teaching. Based on the works of Y. K. Babansky, the authors understand an optimization process as a comparison of diff erent variants of the teaching and a selection of the best one. Comparison is used as a method of teaching foreign languages. In Russia, the fi rst information about the comparative method was associated with the teaching the German language in the 18th century. Since the 19th century, this method is used in teaching kindred languages, for example, Russian language to Slavic students (V. I. Sreznevski). In the 20th century, the comparison becomes the main procedure of the conscious-comparative teaching method (I. V. Rakhmanov) and of the theory of national-language orientation (V. N. Wagner). Thus, comparison turns out to be one of the basic procedures in pedagogy and theory of teaching Russian as a foreign language. It is used both in scientifi c research and in the teaching process.