Abstract: The article is devoted to the problem of forming a source complex on the history of the Spaso-Preobrazhensky Cathedral of the Nizhny Novgorod Kremlin of the XIX - early XX centuries in order to create its scientifically based virtual reconstruction. As a result of many years of work, the author has collected a significant documentary base on the history of the temple, which includes four large groups of sources: written, pictorial (graphic), cartographic and material (museum exhibits). Each of them is analyzed in detail with the allocation of materials that are most important for the three-dimensional reconstruction of the designated historical object. The paper also discusses methods and technologies for analysis, verification and initial digital processing of pictorial sources from its composition. The scientific novelty of the study is expressed in the fact that for the first time a relevant source complex on the history of the Spaso-Preobrazhensky Cathedral of the 1830s was formed, which radically distinguishes this study from previous excursion and tourist virtual reconstructions of this temple. In addition, the technique of digital processing of visual sources and their translation into 3D format, developed by the author and presented in this article, has a certain novelty, which allows to preserve their original appearance as much as possible. The collected documentary base on the history of the Spaso-Preobrazhensky Cathedral of the Nizhny Novgorod Kremlin allowed us to assert the possibility of its authentic historical virtual reconstruction.