Relying on the method of the history of concepts, this paper considers how Montesquieu's treatise The Spirit of the Laws had come to be perceived in Russia by 1762, as well as the existence of the concept of "fundamental laws" in the Russian political lexicon. It is demonstrated that among the Russian ruling elite, The Spirit of the Laws had a number of followers, who, however, did not play a leading part in the domestic policy of Elizabethan Russia. By 1762, the treatise had limited circulation, but the fact that some people knew about its ideas did not mean their full and unconditional acceptance of it. Moreover, these ideas could be perceived very critically, as was demonstrated by F.H. Strube de Piermont, professor of the St Petersburg Academy of Sciences. For the Russian ruling elite, The Spirit of the Laws was not the only work about fundamental laws. By the mid-18th century, discourses about such laws were available in the works of several European authors, including S. Pufendorf and F. Fenelon. In the works of such authors, a combination of fundamental laws with a monarchical form of government was associated with the idea of a contract between subjects and the monarch. According to the resources analysed, this understanding of the contractual nature of fundamental laws influenced the draft of the fundamental laws by I. I. Shuvalov (1760-1761) and the Manifesto on the Freedom of the Nobility by Peter III (1762). By the early 1760s, the concept of "fundamental laws" was an essential part of the political language of the Russian ruling elite, and it influenced the understanding of domestic policy and its goals. However, this was not due to the reception of Montesquieu's ideas. At the same time, the reception and use by the ruling elite of concepts describing the form of government and the concept of "fundamental laws" laid the foundations for the perception of the ideas of The Spirit of the Laws. As a result, the main innovation of this treatise in Russia was not the use of the concept of "fundamental laws", but its reinterpretation.