The aim of the article is to analyze the 1970 constitutional changes influence on the Buryat ASSR authorities functioning with the use of systematic and comparative approaches, and institutional method of research, and also unpublished archival materials. The text of the Fundamental Law of the autonomous republic was promulgated in mass media with a total amount of more than 170 thousand copies. Broad and purposeful explanatory work was carried out by members of the Constitutional commission of the republic, the ideological core group and editorial offices of newspapers, radio and television. The new Buryat ASSR Constitution was officially adopted on May 30, 1978 at the session of the supreme body of the government. Its text included new sections and chapters, and a number of articles were changed and added. The Buryat ASSR was proclaimed a socialist public state. The legal status was determined in detail, as well as the order and forms of activities of the Supreme Council, its Presidium and Council of ministers of the ASSR were regulated. People's Deputies of all levels constituted a single system of the government. The national statehood of Buryatia was limited. The declared and expanded political and social rights of citizens remained declarative in many respects. The unique political party won the constitutional status of leading and directing force of society denying all principles of separation of the authorities and turned into the main element of government institution. At the same time, the system of the state was not ideal. There followed a painful process of familiarizing working people with implementation of government and management. The local councils (sovjets) were supposed to represent workers’ power but remained considerably the power over working masses. Bureaucratization of the councils’ activities grew stronger, the councils were substituted by party committees, stability of personnel turned into their irremovability, stagnation and gerontocracy, Councils’ control over the work of executive bodies required cardinal strengthening. A serious adjustment of the electoral system and democratization of political life of the society was needed. The considered materials can be used for a comparative analysis of activity of public organs of different levels.