Abstract: The subalpine natural secondary forest in western Sichuan is the main forest type of water conservation forest in alpine forest regions of southwestern China, which plays an important role in the carbon budget of forest ecosystems in this region. In this paper, the soil structure and organic carbon distribution characteristics of secondary forests in different successional stages were studied by dry-sieving method and potassium dichromate oxidation-external heating method. It was found that the soil aggregates of secondary forests in each successional stage in this region was relatively strong. The content of large aggregates was the highest in Abies faxoniana and Betula spp. mixed forest, and the formation of large aggregates was negatively correlated with the content of organic matter. The content of organic carbon mainly existed in large aggregates, and the contribution rate of organic carbon in soil aggregates with particle size >5 mm was the highest, with the order of Abies faxoniana and Betula spp. mixed forest > Abies faxoniana forest > Betula spp. forest. The organic carbon content and soil nitrogen were positively correlated. Although the content of large aggregates in Abies faxoniana forest was lower than that in Abies faxoniana and Betula spp. mixed forest, the content of total organic carbon was the highest. The content of microaggregates increased with the increase of successional stage, and the content of organic carbon basically increased with the decrease of aggregate size. When comparing the organic carbon content and contribution rate of different aggregates, it was found that the organic carbon content of <0.25 mm particle size was high but the contribution rate was low, which indicated that the microaggregates had stronger protection for organic carbon and the ranking order was Abies faxoniana and Betula spp. mixed forest > Betula spp. forests > Abies faxoniana forests.