Forty-five percent of darkling beetle species recorded in China occur in the northern arid and semi-arid areas. Some ecological studies have suggested that tenebrionid beetles can be used as effective indicators of vegetation degradation and soil desertification in desert ecosystems because they are well-adapted desert conditions. Large areas of artificial shrubland have been established on China's desert steppe, but little is known about how this shrubland influence ground-dwelling arthropods. We studied the distribution of darkling beetles (Coleoptera: Tenebrionidae) across the ecotone between man-made Caragana intermedia shrubland and natural desert steppe to evaluate the effects of desert vegetation restoration on ground-dwelling beetle assemblages in Northwestern China. Using pitfall traps, beetles were sampled along five transects crossing the boundary between the artificial shrubland and natural desert steppe. The study was conducted from June to October in 2012 in Yanchi, Ningxia, Northwestern China. A total of 1405 tenebrionid beetles were collected, belonging to 13 species and 8 genera. Of these species, Microdera kraatzi and Blaps femoralis femoralis were the most common, accounting for 32.74% and 43.27% of all individuals, respectively. Darkling beetles were divided into three groups by habitat: (1) habitat generalists, which were numerous in all habitats, e.g., M. kraatzi and B. femoralis femoralis (M. kraatzi was most abundant in sandy steppe, while B. femoralis femoralis occurred mostly in shrubland); (2) desert steppe specialists, e.g., Platyope monglica and Scytosoma pygmaeum; and (3) shrub specialists, e.g., Blaps kirishenkoi, Eumylada oberbergeri, Gonocephalum reticuluatum, and Crypticus rufipes. Species richness and Shannon-Wiener diversity were higher at the boundary between shrubland and desert steppe than in either habitat, and abundance was greatest in shrubland, declining towards the desert steppe. However, there were no statistically significant differences between these three indices among the three habitats. Seasonal variation in Shannon-Wiener diversity in the desert steppe was similar to that in shrubland. Activity density in the three habitats were shown with the similar seasonal changes. Analysis of the intensity of edge effects showed positive effects at the edge. Canonical correspondence analysis (CCA) suggested that related species occupied similar habitats. Multiple linear regression showed that vegetation density was related to the activity density of the dominant species, and the vegetation cover and height were important factors associated with beetle evenness and richness indices. Principal coordinate analysis (PCoA) showed that beetle assemblages at the ecotone between the artificial Caragana shrubland and desert steppe showed no significant difference with those in the interior of the artificial Caragana shrubland, suggesting that the community structure of darkling beetles at the ecotone was changing to resemble the assemblages in shrubland.