Background <p>Understanding how tree mycorrhizal types influence soil organic carbon (SOC) mineralization and its temperature sensitivity (Q₁₀) across different aggregate size classes is critical for combating global climate change. However, the specific role of tree mycorrhizal types in SOC mineralization and its Q₁₀ across different aggregate size classes remains unclear.</p> Methods <p>This study conducted indoor incubation experiments to examine the effects of arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) trees on SOC mineralization and its Q₁₀ in different aggregate fractions.</p> Results <p>Our results indicated that AM and ECM trees affected aggregate size distribution. Compared to the ECM tree plot, the AM tree plot showed 9.56% and 4.19% higher proportions of large and small macroaggregates, respectively, while exhibiting 12.67% lower microaggregates. In addition, there were no significant differences in the proportion of silt plus clay. The AM tree plots exhibited higher cumulative mineralization than the ECM tree plots across different aggregate size classes. Cumulative mineralization declined with the increase in aggregate particle size. Except for the silt plus clay fraction, the Q₁₀ values of the AM tree plots were higher than those of the ECM tree plots in other aggregate size classes. Partial least squares path modeling showed that tree mycorrhizal types and soil aggregate sizes influenced SOC mineralization and Q₁₀, through soil nutrients, enzyme activities, and microbial biomass.</p> Conclusion <p>Our study emphasizes that tree mycorrhizal types have a significant impact on SOC dynamics, with AM trees enhancing SOC mineralization and its Q₁₀ at the aggregate levels.</p>