[Objective] The diversity of typical shrub communities in the ecotone of the Ulan Buh-Western Ordos Steppe Desert was researched in order to provide a theoretical basis for protecting biodiversity and for ecological environment construction in the area. [Methods] A vegetation survey was carried out by setting up sample sites of representative community types in the area. The community types, species composition, community characteristics, and species diversity of the main shrub communities in the ecotone were analyzed. [Results] There were 12 families, 30 genera, and 36 species of plants in the area, among which there were more Fabaceae, Chenopodiaceae, Asteraceae, and Poaceae, and more single species. Plants were mainly composed of shrubs and perennial herbs. Most plants were xerophytes. The shrub communities included the Krascheninnikovia ceratoides community, the Scarcozygium xanthoxylon community, and the Tetraena mongolica community in the Western Ordos Steppe Desert, and the Nitraria tangutorum community, the Artemisia ordosica community, and the Ammopiptanthus mongolicus community in the Ulan Buh Desert. The plant density of the shrub community was higher in the Western Ordos Steppe Desert. The importance value, coverage, and aboveground biomass of the shrub community were higher in the Ulan Buh Desert. The species diversity of the shrub communities in the Western Ordos Steppe Desert was generally higher than in the Ulan Buh Desert. The similarity of most communities was low. [Conclusion] The total number of plants in the Ulan Buh-Western Ordos Steppe Desert was relatively few. Perennial herbs and shrubs were the main types of plants in the ecotone. The plants exhibited obvious xerophytic characteristics. The variation range of plant diversity in the Western Ordos Steppe Desert was small and remained at a high level. Community similarity in different habitats was low.