The article shows the approaches to the religious studies of the Reformation that existed on the eve of totalitarianism. Transformations during the Soviet era not only in the political but also in the ideological spheres stipulate an interest to this research area. The consideration to Reformation was given because as well as the Revolution it changed the system of social and religious relationships in society. The primary emphasis was made on the economic and class consequences, which explained an influence of Marxism theory. The article considers other scholarly approaches to this problem, popular before the revolutionary events. Of course, not all concepts are considered. The article is divided into two main bodies, dedicated to the research of N. Kareev and A. Vulfius respectively. More considerable attention is paid to the scholars' scientific views on Reformation, rather than to fragments of their biographies. Some considerations determined the choice. On the one hand, some of these scholars' works were published or reprinted in the early 1920s, with the Civil War barely ended. One of the best examples is the works of A. Vulfius, which were published in 1920-22. On the other hand, their ideas were very popular over the former Russian Empire, which is mostly true from N. Kareev. There is also proof that the researcher had kept up his popularity in Poland despite the Soviet-Polish War of 1919-1920. Their systematic work on the study of the religious beliefs and practices in everyday life has been designed and created by large-scale field research in accordance with the achievements of modern theoretical works. Their hypothesises are of interest because later they will not be popular, including further political events. Nevertheless thrust forward to the fact that in the first years after the end of the Civil war their works were still published. Despite the change of regime, their opinions reflected in these studies were in connection with the past, pre-revolutionary historiographic tradition. In the foremost, it was an influence of European, primarily French and German, ideas. According to the N. Kareev, Protestantism had succeeded not so much due to religious as to social reasons. He explained Reformation in Poland as happening due to the complicated relations of the gentry and clergy. The researcher believed that the Reformation was conditioned on church institution's "spoiling" and on a social opposition. In his opinion, in the Holy Roman Empire this process was due to two circumstances. Firstly by a specificity of the religious spirit, and secondly, by pressure from the papacy. Thus he emphasized the German specificity. The researcher noted other processes in Poland, unlike the Holy Roman Empire. According to N. Kareevthe absence of national opposition to the Pope and own Protestant leaders against the background of heterogeneity within Protestantism led to the rapid ousting of Protestant ideas and the strengthening of the Jesuit order. That is, the researcher drew attention to the fact that the reform events had their specifics depending on the region, especially between Central and Eastern Europe. A. Vulfius noted the imprecise and narrow character of the term "Counter-Reformation' or "Reaction". It was able to cause some confusion. The word 'Reaction' accentuated the opposition against Reformation, and thus upstaged a very deep and interesting inner rebirth of Catholicism. However, one can also talk about similarities in their work. It refers mostly to a periodization of the reformation time. It is possible that L. Ranke's periodization influenced both scholars. More specific differences can be noted than similarities in the works of A. Vulfius and N. Kareev. This is mainly due to the influence of different schools, which not only manifested itself in the events they emphasized while describing Reformation but also and in assessing the nature of the relationship between Reformation and Trent Council Catholicism. For example, A. Vulfius was paying more attention to the spiritual and religious development at that time, and N. Kareev to the social one. Regardless of this, it is important to note that there had existed on the territory of the Russian Empire a rich scientific tradition, devoted in part to the study of Reformation, at the time of both religious and social transformations before the advent of the totalitarian regime. We can also trace the influence of European historiographic traditions, mainly German, including historical and sociological ones, on both scholars.