During the reign of Peter the Great - called the starting point of Russia's modern culture - the Western culture flew into Russian society explosively. As the Western culture spread very rapidly in the wake of westernization policy of Peter the Great, Russia's high society began to be included in the boundary of the Western style culture. Influences of French were so strong at the time that it can be said without exaggeration that Russia's high society in particular was swept in the fever of French in the 18th-19th Century. France, called the center of the western Europe's culture and art in the 18th Century, left remarkable traces in ordinary life of Russia's aristocratic society in various ways. Of these, influence of French was most remarkable encompassing from daily life to the field of thought and concept. This article is an attempt to examine how French that dominated Russia's aristocratic society from the 18th Century to the early 19th Century affected Russia's language culture. Firstly, the study examined influence of French from the social aspect. As ability to speak French functioned as an attribute differentiating the language of aristocrats from that of other classes, Russian society turned to one with distinct language variation by the class. Secondly, the study examined influence of French on Russian, and found that as spoken language of aristocrats with widespread gallicism flew into Russian literary language, status of spoken language rose and the previous equation that literary language was equal to written language became unapplicable. Thirdly, strong influence of French throughout the 18th Century contributed to change of Russian people's perception of their native tongue. Conflicts between Church Slavonic and Russian - dominating until the 17th Century - became weaker gradually and under the strong influence of French, the two languages were incorporated into a tradition of ethnic language and as a result there prevailed perception that Slavonic-Russian combining these two were in opposition to French.