The dependence of the dielectric constant on the composition of alloys was determined for the systems: 1) (Sb₁₉Ge₂₂Se₅₉)_1-xCo_x; and 2) [(As₂Se₃)_1-y(Cu₂Se)_y]_1-x[Me$ -2$/ Se₃]_x, where y = 0.0, 0.1, or 0.23 when Me = Cr and y = 0.3 when Me = Mn. Within the sensitivity of the method employed, the alloys of the system [(As₂Se₃)_0.7(Cu₂Se)_0.3]-MnSe with 0 ≤ 100x ≤ 1.2, where x is the atomic fraction of Mn are uniform glassy materials. Alloys of the composition 1.2 < 100x ≤ 1.6 contain microcrystalline inclusions based on Mn compounds with a virtually metallic type of conductivity surrounded by an isolated layer whose thickness is on the order of tens of angstroms. When 100x > 1.6, the crystallization process covers a significant part of the volume.