Аннотация:We study numerically the change in characteristic sizes of light bullet’s (LB’s) high intensity region and the energy localized in it during filamentation of femtosecond mid-IR wave packet in LiF under the conditions of anomalous group velocity dispersion. It is found that in the process of LB’s propagation, the duration and diameter of a region with an intensity above 50 TW/cm2, as well as the amount of energy contained in this region, vary with distance. General character of the process of light bullet’s formation in different dielectric media allows to extend obtained results to the transfer of high-density energy in atmosphere.