The energy transfer between the rare-earth ions in Y s SiO 5 -Ce, Tb crystals has been investigated with the use of the methods of luminescence spectroscopy with subnanosecond time resolution and excitation by pulsed synchrotron radiation (SR). Effective nonradiative energy transfer between Ce 3 + and Tb 3 + -ions which is realized by the inductive resonance mechanism has been observed. The absolute constant of the energy transfer speed K t and the probability of transfer have been determined. A dependence of the energy transfer parameters on the SR-excitation density has been discovered and investigated. Increasing of the density of the SR-excitation by a factor of 10 results in the increase of K t from 4.8 10 8 up to 1.7 10 1 0 mol - 1 s - 1 .