The article analyses «Home Notes Journal – a source of a memoir type, unpublished and insufficiently explored dealing with the siege of Orenburg during Pugachev's Rebellion of 1773–1775. The purpose of this article is to examine the source from the author`s social psychology not from its actual side. The work aims to reconstruct the author's perception of the rebels, his interpretation of the nature of the historical event, its social basis and its causes.