The work presents the results of a study on the distribution of the theory of the Masonic conspiracy in Russian social and political thought at the beginning of the 20th century. Factors and sources of formation of anti-Masonic representations are revealed. Development of this theory is defined by authors of article as reaction to the system transformations happening in Russia and the indicator of the coming revolution. Classification of the basic approaches to reveal the essence of the Masonic conspiracy is carried out. Investigations of a Masonic plot from Department of police are exposed to separate consideration. The authors come to the conclusion that the theory of the Masonic conspiracy became an important compound component in the ideology of the Russian right at the beginning of the twentieth century.