The history study of nationalist parties in the 20th century is the subject of close attention of many researchersgermanists. However, the history of the Sudeten-German party in Czechoslovakia in the 1930s does not often become an object of research. The purpose of the article is to consider the activities of the Sudeten-German party, to highlight the key reasons for its emergence. Particular attention is paid to the evolution of the party leaders' views on the way to unification with Nazi Germany. Also, the work proposed, if possible, an objective analysis of the essence of Henlein movement. The urgency of the problem is substantiated, first of all, by the fact that according to a similar scenario events, developed and continue to develop on the territory of the former Yugoslavia, the Soviet Union, especially in the Baltic countries, where the Russian-speaking population makes up a significant part, like the Sudeten Germans in Czechoslovakia at their time, however, they are also targeted by the discriminatory policy of the authorities. The source base was made up of the documents collected by the Czechoslovak researcher V. Kral and published by him in 1964. As part of these materials, a large group of sources can be distinguished, which make up materials at the meetings of the main leadership in the Sudeten German Home Front - the Sudeten German Party in the period from 1933 to 1937, early 1938 and the speech by the leader of the Sudeten German Party K. Heinlein. Since the early 1990s we can talk about the renaissance of the historiography of the Sudeten-German history, mainly due to the development of archives in Germany, the Czech Republic and Slovakia. The First World War did not contribute to the resolution of national contradictions. After the end of the First World War the Sudeten Germans were also included in Czechoslovakia at the behest of the Entente. The Sudeten-German party of K. Henlein took an active position in this struggle. Summing up, the authors conclude that the question of the nature of Henlein movement is controversial. Henlein movement really resembled the Nazi party in Germany, but at the initial stage of its activity in 1933-1936. However, as the Czechoslovak authorities opposed, pressure from the Nazi party in Germany and the strengthening of the right-wing radical branch, the Sudeten German Party practically lost its characteristics and turned into an analogue of the National Socialist German Workers' Party. This fact largely predetermined the radical solution of the Sudeten-German question through the Munich agreements on September 29, 1938, when the border regions of Czechoslovakia were annexed to Germany. Undoubtedly, these agreements were in the interests of the majority of the Sudeten Germans, who, however, once again became victims of the big European politics.