[en] A brief review on the state of the problem of occurrence of light elements, physics of shearing reactions and nucleosynthesis, caused by the observed fluxes of galactic cosmic rays is presented. Special attention is paid to ⁷Li nucleosynthesis, revealing interesting aspects of star physics, the problem of the effect of low-energy cosmic ray flux, strongly modulated by solar wind and solar magnetic activity, nucleosynthesis in red giants, explosions of novae and early stages of the Universe evolution which are of particular interest among them. The conclusion is made, that light elements Li, Be and B present a unique instrument for the analysis of cosmologic problems, as well as for the comprehension of the physics of cosmic rays and chemical evolution of galaxies