Purpose <p>Understanding the effect of land use change on different organic carbon components of grassland soil is crucial to predict the role of grassland in reducing atmospheric CO₂ concentration, developing strategies for carbon sequestration of grassland, and for the sustainable utilization of grassland resources.</p> Methods <p>We estimated different components of soil organic carbon in the 0–30&#xa0;cm soil layer under different land uses (i.e., free grazing in winter - WG, enclosed grazing land – FL, and annual oat pasture - OL) on the Tibetan Plateau. Field samples were collected following the five-point sampling method combined with acid hydrolysis and other analysis methods.</p> Results <p>Our results showed that different land use modes have different distribution modes of above-ground and underground productivity. The content of recalcitrant carbon (RC) in the 0–10&#xa0;cm soil layer was the highest in the FL, and the content of mineral-associated organic carbon (MAOC) in each soil layer was the highest in OL. Soil surface (0–10&#xa0;cm) microbial biomass carbon (MBC), readily oxidized organic carbon (ROC) content, were significantly higher in WG and FL than in OL, but there was no significant difference in dissolved organic carbon (DOC) content between land uses, and particulate organic carbon (POC) content in OL was the lowest. Soil physical and chemical properties were important reasons for the differences in soil carbon pool composition observed under different land uses. Our results suggest that WG is beneficial for the accumulation of soil recalcitrant carbon. After prohibition of grazing, soil recalcitrant carbon content is reduced and the stability of soil organic carbon is weakened.</p> Conclusions <p>This study highlights that different land uses mainly affect soil organic carbon components by affecting soil physical and chemical properties, especially the contents of different forms of soil nitrogen.</p>