1. Ecological theories and experimental evidence indicate that human activity induced losses in biodiversity can have substantial impacts on multiple ecosystem functions. It remains unclear, however, how grazing affects grassland biodiversity and ecosystem multifunctionallity (EMF). 2. Here, we assessed the grazing effects on different dimensions of biodiversity (i.e. plants and soil microbes) and EMF based on a 11-year field experiment in a semi-arid grassland. 3. We found that soil organic C, available nitrogen, and plant functional diversity all decreased even at low grazing intensity while aboveground primary production and bacterial abundance decreased only at high levels of grazing intensity. Grazing pressure effects on EMF can be well predicted by changes in plant functional diversity. 4. Structural equation models reveal that EMF was dominated by grazing pressure and was not directly affected by plant or microbial composition. 5. Synthesis. Our results showed that ecosystem functions differ in their sensitivity to grazing intensity, limiting the effectiveness of a target grazing level to achieve multiple goals in the Eurasian steppe. These findings suggest that grazing-induced alterations in interactions among plants, microbes and environmental factors critically affect the grazing threshold and deserve some major attention in decision-making for grazing.