The history of the illegal press in Siberia since the creation of the Soviet state upto the USSR collapse was studied. Main tendencies of unsanctioned publishing activity in the Soviet period are characterized. The study is based on a wide range of sources, many of them are introduced into scientific circulation for the first time. It was found that the forms and content of uncensored editions were conditioned by a specific historical social-political conditions and social-cultural processes. The continuity of pre-revolutionary traditions of the underground press was traced. For the first Soviet decade (1920s-1930s) illegal publications were means of ideological confrontation and existed mainly in the form of propaganda leaflets. As far as political conflicts were weakened from «Ottepel’» to «Perestroika», self-publishing became not only a mouthpiece of the opposition, but also an additional information channel. Unauthorized printed products are modified, their thematic spectrum is widening. In 1987-1991 uncensored press was gradually emerging from the underground and was transformed into the alternative press reflecting processes taking place in the country: the crisis of the USSR political system, a multi-party system establishment. Unauthorized publishing activity investigation fills the gaps in the history of regional book business, as well as provides insight into the evolution of the Siberian society mentality.