In work a problem was posed to use a method of polyhedrons Voronoi for the analysis of a structure of crystal, subjected impact loading, on various stages of process. Polyhedrons Voronois for facecentered tetragonal lattices with casual thermal fluctuations are beforehand investigated. Thus is shown, that a method of polyhedrons Voronoi allows to identify lattices and to determine a degree it tetragonality.The structure impactloading solids is obtained by computer simulation by a method of molecular dynamics. The accounting mesh represented volume as a parallelepiped with a relation of sides 1:1:3, in which are located 640 atoms of argon. The analysis of this structure a method of polyhedrons Voronoi has shown that immediately for front of a shock wave passage of a cubic lattice in tetragonal lattice happens. Is shown that through a time interval equal sec inverse process of a relaxation tetragonal of a lattice in a cubic lattice begins. A velocity of a shock wave is defined which will be not bad agreed an ex

perimental value.