<p>Grassland management and global change can alter the proportion of plant above- and belowground inputs to soil, thereby influencing soil organic carbon stocks in globally distributed grasslands. While studies have suggested that aboveground and belowground inputs can play different roles in SOM formation, experimental evidence for this comparison is scarce in Asian grasslands. In 2018, we established a grassland experiment with four plant input pathways: no input (NI), aboveground input (+ A), belowground input (+ B), and both above- and belowground inputs (+ A + B). Inputs were manipulated by periodically removing roots and shoots during the growing season at NI and + A plots and transferring aboveground biomass from + B to + A after the growing season. We quantified the dynamics of soil organic matter (SOM) and dissolved organic matter (DOM), free particulate organic matter (fPOM), occluded particulate organic matter (oPOM), mineral-associated organic matter (MAOM), and microbial necromass during the subsequent 5 years. SOM content at NI plot did not change over this time, but was significantly lower than those in the plant input treatments (i.e., +A, +B, + A + B) after 5 years of manipulation. We found similar SOM content between plant above- and belowground inputs during 5 years, as well as for fPOM, oPOM and MAOM. DOM content was also similar between the two inputs, but the absorption ratio of DOM at 250&#xa0;nm to 365&#xa0;nm (A₂₅₀:A₃₆₅), which is indicative of DOM aromaticity, was lower in the aboveground input plot than the belowground input plot, suggesting a higher degree of aromaticity under aboveground inputs. Overall, our results underscore the equal importance of plant above- and belowground inputs in the formation of POM and MAOM, at least within 5 years. These findings will offer useful insights for grassland managers and policy makers in understanding and predicting SOM sequestration under aboveground removal conditions.</p>