Aims <p>We aimed to explore that how grazing pressures impact photosynthetic carbon allocation between above- and below-ground and carbon flux in grasslands.</p> Methods <p>An in situ ¹³C labeling experiment was carried out in a temperate grassland with four grazing intensities: no grazing, light grazing, moderate grazing and heavy grazing.</p> Results <p>Our results revealed that the grazing exclusion treatment exhibited higher carbon stocks in plants, roots, and soil than the other grazing intensities. Plants remained higher proportion of photosynthetic carbon to shoots in the control (29.51%) than in the other grazing treatments (light: 26.35%; moderate: 25.58%; heavy: 23.50%) after 30&#xa0;days of the ¹³C labeling. The percentage of ¹³C allocated to roots was higher in heavy grazing (19.14%) than in un-grazing (14.80%), light (15.49%), and moderate grazing (17.61%) treatments. In contrast, ¹³C recovery in soil was higher in moderate grazing (40.93%) than in heavy (35.25%), light (33.42%), and no-grazing (31.68%) treatments. The ¹³CO₂ released by roots and soil microbial respiration was greater (16.52%) in no-grazing than in other grazing treatments.</p> Conclusion <p>In summary, moderate and heavy grazing promoted the allocation of photosynthetic carbon to belowground parts and reduced carbon dioxide emissions. However, heavy grazing still leads to a decline in soil organic carbon compared to grazing exclusion. As a survival strategy against grazing, this shift reduces short-term CO₂ loss but may not enhance long-term storage under heavy grazing. Our findings highlight that understanding long-term grazing effects is crucial for evaluating grassland carbon sequestration and developing adaptive management strategies.</p>