Background and Aims <p>The rhizosphere plays a critical role in the formation and stabilization of soil aggregates, as well as soil organic carbon (SOC) dynamics. This study aimed to investigate how rhizosphere influences SOC and its fractions at the aggregate scale.</p> Methods <p>We collected rhizosphere soil samples across four dominant tree species (<i>Fraxinus mandshurica</i>, <i>Larix gmelinii</i>, <i>Betula platyphylla</i>, and <i>Pinus sylvestris</i>) in Northeast China.</p> Results <p><i>F. mandshurica</i> had the highest SOC stocks, 1.67 times higher than <i>L. gmelinii</i>, which had the lowest SOC stocks. Across all tree species, rhizosphere soil generally contained higher SOC content than non-rhizosphere soil in most aggregate size classes, except for large macroaggregates. The SOC content varies with the aggregate size class. Microaggregates had the highest SOC content in the rhizosphere and non-rhizosphere soil. Both particulate organic carbon (POC) and mineral-associated organic carbon (MAOC) were predominantly concentrated in microaggregates. The rhizosphere soil of <i>F. mandshurica</i> had the highest MAOC content (14.96 g/kg) among the four tree species and the lowest POC/MAOC ratio (0.77). Correlation analysis revealed a stronger relationship between SOC content in rhizosphere aggregates and rhizosphere SOC content than in non-rhizosphere. The POC/MAOC ratio in small macroaggregates was the strongest factor driving variations in aggregate-associated SOC and its fractions.</p> Conclusion <p>Rhizosphere obviously influenced SOC and its fractions at the aggregate level and enhanced SOC sequestration across all tree species.</p>