The relationship between species diversity and aboveground biomass may be affected by environmental conditions and anthropogenic activities and is one of the central topics in ecological research. However, little is known about the relationship between the biodiversity and biomass of sandy plants during community succession in semi-arid deserts. In the Horqin Sandy Land of Inner Mongolia in China, vegetation restoration occurs under proper management regimes in fragile environmental conditions, e.g., enclosing and non-grazing. During the process of restoring succession, shifting, semi-shifting or semi-fixed, and fixed sandy dunes correspond to early, middle, and late succession phases. Therefore, a field experiment was performed to examine the aboveground biomass and species diversity of sandy communities during the process of restoring succession. In early April 2014, six communities that corresponded to succession times of 1, 3, 5, 12, 15, and 20 years were selected as experimental sites. At each site, three parallel 200m line transects (20 m apart) were established along a sandy dune (across the windward slope, dune crest, and leeward slope). For each transect, 20 sampling points of 1m×1m were established at 10m intervals. At each of the 360 sampling points, species composition, coverage, height, and density were surveyed; whereas aboveground biomass was measured using a level cutting method, and the dry weight of the biomass was measured after drying in an oven at 85℃ for 24 h. The frequency of each species was calculated at each of the six sites, based on the frequency of occurrence among the 60 sampling points. (1) The number of plant species increased by 400% from the shifting sandy dune to the fixed dune, and annual herbaceous plants were dominant in each community, although perennial species increased with succession. In the shifting sandy dune community, the dominance of the Chenopodiaceae was the most exaggerated, and this level of dominance gradually decreased in the semi-fixed and fixed sandy dunes. Meanwhile, the richness and dominance of grass species gradually increased during the process of restoring succession. There was a significant difference among the aboveground biomass of six communities (F=18.926, n=360, P < 0.001), and the aboveground biomass increased by 580% from the shifting sandy dune to fixed sandy dune. (2) The Simpson, Shannon-Wiener, and evenness indices gradually increased along the restoring succession gradients. (3) Regression analysis indicated a marked relationship between aboveground biomass and species diversity. The fitting curve was a negative quadratic or a single peak function. The results of the present study support the single-peak model of the relationship between biodiversity and productivity of plant communities, with maximum biodiversity occurring at an intermediate level of plant productivity.