The alloy system cadmium-antimony-zinc was investigated using specimens of variable composition obtained by vacuum deposition of alloy components. The formation of a continuous series of solid solutions in the pseudobinary section ZnSb-CdSb was verified, and it was established that in the pseudobinary section Zn3SB2-Cd3Sb2 there is a wide range of solid solutions with a structure similar to that of metastable compound ξ-Zn3Sb2. Type Sb2Zn3xCd3(1-x) alloys prepared in the usual way have a thermal emf of up to 450 μV/deg and a type ξ-Zn3Sb2 lattice.