A possibility of preparation of alloys containing rare-earth elements by high-temperature exchange reactions with simultaneous alloy-formation is shown. Investigations on choosing electrolyte for production of such alloys have been carried out. Analysis and the properties of model and real salt mixtures were found to well agree with each other. Therefore preliminary modeling of salt mixtures has an important technological significance. The process to produce alloys on the basis of magnesium and aluminum with simultaneous alloying by other components has been investigated. The effect of process conducting temperature, duration of reaction, electrolyte composition, metal to salt ratio on concentration and degree of rare-earth metal yield into the alloy was considered.