The changeover of the vegetation of the steppe zone into the desert zone takes place on the plains of the southeast of the European part of Russia. In 1907, N. A. Dimo and B. A. Keller have proved an existence of special semidesert zone in the Northwestern Precaspian. However, from the geobotanists point of view the term “semidesert” should be used for the name of a natural zone, and the type of vegetation that characterizes a zone should be set on according to dominant life forms (ecobiomorphes) forming a plant community. The paper is justified the affiliation of the Northwestern Precaspian vegetation to the steppe zone, subzone desert steppes. The method of studying the spatial-temporal changes of vegetation was the ecological and topological profiling conducted repeatedly in different years. The Sarpinskaya Lowland and Chyornye Zemli landscapes were studied as a typical for the Northwestern Precaspian. It is established, that the features of vegetation cover is defined by a combination of zonal turf-grasses communities with intrazonal xe-ro-halophytes groups. The displacement of the turf-grasses by Artemisia typical for northern deserts does not occur in the Northwestern Precaspian. Intensive agricultural activity is a cause of degradation of vegetation and anthropogenic desertification of the landscape.