Ecological stoichiometry represents the balance of multiple chemical elements in ecological interactions and processes. Theoretically, if there are clear relationships between the C:N:P ratios and maximum relative growth rate, relationships between life history evolution, the physiological demand for major elements, and even ecosystem processes would be expected as well. Indeed, many studies have shown clear relationships between plant growth rates and plant N:P ratios. However, whether C:N:P ratios can affect species diversity and community biomass remains unclear, and requires testing. We therefore investigated several Artemisia ordosica communities from sandy soils in the Ningxia Habahu National Nature Reserve. More specifically, we chose an (1) A. ordosica-Corispermum deslinatum+Salsola sp. community, (2) A. ordosica-Calamagrostis pseudophragmites community, (3) A. ordosica-Pennisetum centrasiaticum+Aneurolepidium dasystachys community, (4) A. ordosica-P. centrasiaticum community, (5) A. ordosica-Sophora alopecuroides community, and an (6) A. ordosica-A. scoparia-S. alopecuroides community. From these communities, 1 and 2 represent the early successional stages of an A. ordosica community; 3 and 4, the middle stages; 5 and 6, the final stages. We determined foliar C, N, and P concentrations of the plants from the investigated communities, and analyzed the relationships between the plant leaf C:N:P ratios and the corresponding community biomass and species diversity. The results showed that, in the early stages of A. ordosica community development, the plant growth was primarily limited by N, whereas in the middle and final stages, plant growth gradually changed from being N limited to being P limited. The early stage plants had the highest foliar C:N ratios, and the lowest N:P ratios, whereas the final stage plants had the lowest C:N ratios and highest N:P ratios. Plant growth is often limited by N or P element in sandy soil due to the sterile nutrition regime and lower N and P concentration in soil. According to Growth Rate Hypothesis, the rapidly growing organisms commonly have lower biomass N:P ratios. And our results show that the plants have a lower biomass N:P ratio in early stage while a higher biomass N:P ratio in final stage of A. ordosica community. In other words, the plants grow more rapidly in early stage but more slowly in final stage, which is in line with the actual investigation. For early stage plants, the soil water is more abundance, and the low biomass N:P ratio promotes the rapid growth of the plants, while in final stage, the soil is relatively short of water, therefor more P in plant is needed to resist the water stress by protein synthesis, thus higher biomass N:P ratio limits plant growth. In this paper, the results of regression analysis show that with increasing foliar C:N ratios, community biomass decreased significantly, and species diversity deceased as well. In contrast, with increasing foliar N:P ratios, the biomass and diversity both significantly increased. In sum, the ecological stoichiometry has an important effect on species diversity and biomass in A. ordosica communities.