This article is dedicated to representation of the myth of “proletarian dictatorship” in the Soviet constitutionalism. Having emerged in the XIX century, this mythologem experienced certain transformations as a result of targeted work of the party leaders, legal experts and scholars on creating the first Soviet constitution. Later, its ideological content received normative consolidation in legislation. A symbolic reflection of revolutionary myth became the national holidays, demonstrations, cinematography and theatre, banners and other cultural phenomena that contributed to formation of the new civil consciousness. The authors trace the origin of the concept of “proletarian dictatorship”, as well as its further evolution in Lenin’s doctrine on the state. The description of symbolic practices of representation of ideological framework of the Soviet revolutionary regime allows demonstrating the practical implementation of the new type of constitutionalism – the Soviet. The article substantiates the gradual arrangement of the idea of “proletarian dictatorship” as a fundamental myth of the early Soviet State, as well as examines its visual and communicative aspects. The novelty of this historical-legal research is defined by the use of interdisciplinary approach and comprehensive analysis of the Soviet national ideology. The conclusion is made that the legal ideas contained in the Soviet constitutional doctrine proliferate and reproduce through large-scale cultural manifestations that create revolutionary institutions and examples of civil behavior. At the same time, the myth of “proletarian dictatorship” serves as distinct cultural foundation for the new political legal regime that expresses the essence of the Soviet constitutionalism.