Long-term vegetation restoration projects have been implemented on the Loess Plateau to enhance carbon sequestration in ecosystems. However, the trade-off between active and stable carbon pools following long-term vegetation restoration remains unclear. Understanding these dynamics is crucial for accurately assessing restoration benefits and guiding forest management decisions. Therefore, this study aims to quantify the trade-off between active and stable soil carbon pools under long-term vegetation restoration and to identify the relative roles of vegetation attributes and soil properties in regulating soil carbon stability. In this study, we investigated soil carbon stability in a typical catchment of the eastern Loess Plateau with more than 30 years of vegetation restoration, including three planted forests-Pinus tabulaeformis, Platycladus orientalis, and Robinia pseudoacacia -each dominated by a single species, as well as one natural secondary forest. Vegetation attributes, soil properties, and 13 soil carbon components across the 0-200 cm profile were measured over multiple growing seasons (2020-2023) for a total of 2640 soil samples. The soil carbon components were classified into active and stable soil carbon pools to assess changes in carbon stability following long-term vegetation restoration. The results indicated that (1) natural secondary forests had higher active and stable carbon pools in the surface soil (0-40 cm) compared to the planted forests, while deeper layers (40-200 cm) exhibited higher stable carbon and lower total carbon content. (2) Trade-off analysis showed that active soil carbon dominated across all vegetation types as organic content increased, suggesting potential changes in carbon stability following restoration. (3) Partial least squares path modeling (PLS-PM) demonstrated that vegetation attributes (e.g., plant height, biomass, canopy coverage) significantly influenced stable soil carbon, while affecting active carbon indirectly through changes in soil properties like bulk density. These findings underscore the importance of vegetation attributes and soil properties in managing carbon stability in ecosystems, with implications for carbon management in the Loess Plateau and other similar environments.