【Objective】Soil is composed of different size particles, and the properties of each particle and their spatial position in the soil are different. However, prior studies focused on a small range of different aggregates or particle sizes. Thus, this study aimed to investigate different carbon changes in each particle with a wide range and evaluate the role of the turnover and stability of soil carbon for each particle in bulk soil. 【Method】After collecting soil samples from subtropical broad-leaved forest, the soil particles (> 2 000, 2 000-250, 250-53, < 53, 53-20, 20-2, < 2 μm) were obtained by physical fractionation. Moreover, the mineralization experiment was carried out with the same soil weight for each particle and bulk soil to study the difference in mineralization amount, carbon change trend and their relationship. Furthermore, after the dimension reduction of seventeen variables, a composite characteristic index was considered for each soil particle by principal component analysis. 【Result】 Although all soil particles were provided as the same amount for incubation to study their different carbon mineralization, their proportion in bulk soil was used to simulate their summation and compare them with bulk soil. The calculated sum values in cumulative CO₂ emissions, total carbon, C/N, aromatic index, and free oxide iron content for all soil particles according to the proportion of each particle in bulk soil are 95.0%-101.8% of the bulk soil. In addition, it was 132.6% and 116.7% for the calculated sum values of the proportion of specific surface area and total pore volume in bulk soil. It was also observed that the cumulative CO₂ emissions of <2 μm and 20-2 μm particles were significantly higher than those of other particles and bulk soil. The correlation analysis showed that the cumulative CO₂ emissions of bulk soil or particles were positively correlated with specific surface area, total pore volume, total carbon, DOC, MBC, readily oxidized carbon, and free iron oxide, but negatively correlated with C/N. Moreover, this correlation analysis would be altered when soil particles were considered as size group analysis rather than including all. The factor analysis of sixteen indexes for each particle showed that the composite characteristic index was the highest for < 2 μm and 20-2 μm particles, which means they have the most role in bulk soil. 【Conclusion】Physical fractionation of bulk soil facilitates the study by isolating the individual particle, but also amplifies the role of the individual, especially for < 2 μm and 20-2 μm. These different results in soil particles and bulk soil suggest that the carbon change in bulk soil can be traced back to the different changes in carbon in each particle and their relationships. The encapsulation of small-size particles (<2 μm and 20-2 μm) by large-size particles or aggregation might be one mechanism for reducing carbon mineralization, which is conducive to maintaining soil carbon stability or storage.