Previous studies have demonstrated positive net primary production effects with in-creased precipitation in semi-arid grasslands of Inner Mongolian. The knowledge of the store and storage potential of carbon (C) and nitrogen (N) can help us to under-stand how ecosystems would respond to anthropogenic disturbances under different management strategies. Therefore, we carried out research on the storage of organic C and N in four sites where the floras and landform were similar but the intensities of disturbance by grazing animals varied. The primary objective of this study was to pinpoint how the store and storage potential of C and N would respond to grazing exclusion and precipitation. We determined concentrations of both soil organic car-bon (SOC) and soil total nitrogen (TN) in the 0–50 cm soil layers. Concentrations of microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) were measured by an innovative method in our study. Additionally, soil bacteria and fungi content were determined in the 0–50 cm soil layers. The total C , N , MBC and MBN storage were significantly different among the four grasslands (P<0.05), and they all decreased substantially with grassland degradation and increased to a significant extent with the introduction of natural grassland (ND). More than 90% C and 95% N stored in soil were lost, while they were minor in other pools (including those stored in above-ground biomass, litter, and roots). It is inter-esting to note that micro-aggregate is a limiting factor to soil and microbial nutrients pool compared to precipitation. The limit range of C and N storage observed in these grassland soils suggests that enclosed-fence may be a valuable mechanism of seques-tering C in the top meter of the soil profile. The results of this study can provide a basis for better recovery of grassland that grazing disturbed in semi-arid areas.