Based on the study of electionsElections and activities of deputies from Belarusian provincesBelarusian provinces in the StateState DumaState Duma the concept of the historyHistory of parliamentarism in the territory of Belarus during the period of its being a part of the Russian Empire is developed. The connection between the electoral legislation and social characteristics of the representatives of the Belarusian provinces in the Duma is established. It is proved that the deputy corps chosen in accordance with the electoral law of 11 December 1905 did not reflect the social and national composition of the Belarusian lands population. Socially, the deputies of the State Duma of all convocations from Vilna province and from Minsk province in the First Duma represented mainly Polish landowners, with large landowners being in the majority. The new electionElections rules introduced on 3 June 1907 led to a more equitable representation, enabling the increase in the number of Belarusian deputies. The social characteristics of the deputies of the III and IV StateState DumasState Duma from Vitebsk, Grodno, Minsk and Mogilev provinces generally corresponded to the social composition of the population. The specifics of the deputies’ socio-political and legislative activities are revealed, showing that the legislative measures developed were aimed at the real improvement of the life of the population of the region, mainly the poor.