The taxonomic status of the Mongolian saiga has been considered. Data are provided about historical findings, and its possible relationship to the Pleistocene saiga (Saiga borealis) is reviewed. The current distribution and the changes in the Mongolian saiga abundance during recent decades are discussed on the basis of published data and the author's field observations. Organization of a reserve in Shargin Gobi and additional protected territories beyond its limits is substantiated, where some animals from the main preserved population should be reintroduced. This will allow preservation of this unique dweller of semideserts in western Mongolia during unfavorable conditions, such as epizootics, starvation, etc.