The Database of Eurasian beaver (Castor fiber L., 1758) in Nature Reserves and National Parks of Russia is a first checklist of the actual locations of present habitation of the Eurasian beaver in Russia. The Database was developed at the A.N. Severtsov Institute of Ecology and Evolution, RAS (Moscow, Russia) and is maintained by a group of editors and contributors. Information relates to the species rank. It concerns both animals and traces of their activity. Traces of beaver’s activity are clearly visible and species-specific. They can be confused only with activity traces of closely related species - Canadian beaver (Castor canadensis Kuhl, 1820), which according to current data is not widespread in Russia, and there are very few sympatric zones of both species. The history of reintroduction and the subsequent resettlement of the Eurasian beaver makes it very likely that the information included in the dataset refers to Castor fiber L., 1758, and the finds of traces of beaver activity are equated to the beavers themselves. Materials were collected in the process of monitoring observations of beavers in Russia in the reserves and national parks of the federal level (hereinafter referred to as Specially Protected Natural Areas - SPNA). All persons providing material (the contributors) are included as authors of the dataset. Obtained data cover about half of SPNA, where the Eurasian beaver occurs. The presented dataset serves as a source of information on the distribution of the Eurasian beaver in Russia and may be of interest for a detailed study of the distribution of beavers and traces of their activities within each of the SPNA. The amount of material presented for each SPNA was determined by the wishes of the contributors. All data are licensed under a CC BY 4.0 and are available through the Global Biodiversity Information Facility (GBIF). Database of Eurasian beaver (Castor fiber L., 1758) in reserves and national parks of Russia is a service to the scientific community and the general public, including administrations, companies, and non-governmental organizations.