The models of random media used at present in describing polycrystal scatteringcannot explain some experimental facts, such as the double-scattering peak in the energy spectra of reflected ions. Two models of simulation of ion interactions with polycrystals are proposed here, namely 1) the model of random filling of the coordinative spheres in which the polycrystal is represented by a set of singlecrystal coordinative spheres with arbitrary positions of atoms and the distances between atom may sometimes be smaller than those in single crystal, a fact that can be treated as the presence of an imbedded atom; 2) the model of arbitrary selection of the bombarded face in which the surface and incidence planes are selected randomly for each ion (or of a group of ions). In both models, the atoms are free, the Born-Mayer potential is used, and thermal vibrations of atom are included. A good agreement with experimental results has been obtained in both methods.