The paper is devoted to the investigation of behaviour of material under impact loading. Two structure levels of deformation was took into account. At microlevel the conditions of existence of stable dislocation groups formation and their distribution were obtained. These groups were considered as an inclutions with finite mass at the next structure level of deformation. The influence of the mass and position of the inclusion on the stress field in material was studied. For some particular forms of loading it was shown how deformation depends on the characteristics on the inclusion.