The contribution of the Russian physicists to the study of the features of X-ray radiation and the development of options for its application in practice is discussed. Russian scientists (F.F. Petrushevksy, A.S. Popov, P.N. Lebedev, I.I. Borgman, N.G. Egorov, O.D. Hvolson and others) took an active part in proliferating the information about X-rays and their properties. V.S. Kravchenko, a naval medical officer, in 1904 for the first time in the history of marine medicine used X-rays for the diagnostic purposes in the conditions of a sea voyage on board the Aurora cruiser. G.V. Wulf gave a theoretical justification for the results of L. Bragg's research on the reflection of X-rays from the mica cleavage plane. In1914, atalented engineer N.A. Fedoritsky prepared and implemented a technical project of a car X-Ray cabinet. In the laboratories of the Leningrad Institute of Physics and Technology (founded in 1918 by A. Ioffe), a scientific base was created for the research of X-ray physics and the development of X-ray diffraction analysis in the Soviet Union. The contribution of I.B. Borovsky, M.A. Blokhin, E.E. Weinstein, K.I. Narbutt, R.L. Barinsky, N.I. Komyak, N.F. Losev and M.A. Kumakhov is briefly examined. The author focused on one of the directions of X-ray spectral analysis - its use to determine the chemical composition of materials. The author shares N. P. Ilyin's conclusion (2002): Our specialists developed almost all the main areas of X-ray spectral analysis, and they were ahead of their foreign colleagues in solving a number of theoretical and methodological issues. Key words: 125 years since the discovery of x-rays, the contribution of Russian physicists DOI: http://dx.doi.org/10.15826/analitika.2020.24.1.008 A.G. Revenko Institute of the Earth’s Crust, SB RAS, 128 Lermontov St. , Irkutsk, 664033, Russian Federation