[Objective] This study aims to quantitatively assess the carbon storage and carbon sequestration potential of newly added afforestation in the hilly areas of the Loess Plateau, thereby provide theoretical support for optimizing forest carbon sink management and trading in the local area and similar regions [Methods] Youyu County, Shanxi Province, was selected as the research area. First, data related to artificial afforestation projects implemented in the county from 2012 to 2024 were systematically collated. Then, the biomass method and the Logistic growth curve model method were jointly applied to estimate the carbon density and carbon storage of different carbon pools (including biomass carbon pools, dead organic matter carbon pools, soil organic carbon pools and total carbon pools) in the newly added afforestation area of the study area. On this basis, the future carbon sequestration potential of these afforestation areas was further predicted. [Result]① From 2012 to 2024, the carbon storage increased from 61,800 tC to 249,160 tC, an increase of 40.29 times. The inclusion of baseline soil carbon storage within the original non-boundary was the core driving factor for the increase in carbon storage. ②If the contribution of the baseline soil carbon storage from the newly added afforestation is not taken into account, the carbon storage in 2024 will be 505,200 tC, with biomass carbon storage accounting for 93.19%, making it the main carbon pool. The total carbon density in 2024 will be 14.98 tC/hm2, which is lower than the current carbon density of all forests in China. In terms of tree species, the carbon storage proportion of the Pinus sylvestris var. mongolica in 2024 is 79.57%, making it the main carbon-sequestration tree species. The carbon density of mixed coniferous and broad-leaved forest and Pinus sylvestris var. mongolica are significantly higher than that of other tree species, indicating that these two types of trees have greater carbon sequestration potential when planted locally. ③ It is estimated that by 2060, the carbon storage and carbon density will reach 478,430 tC and 141.86 tC/hm2 respectively, and the carbon density will be slightly higher than that of China's national forests. Pinus sylvestris var. mongolica remains the main carbon-sequestration tree species, but mixed coniferous and broad-leaved forest have greater carbon sequestration potential due to their higher carbon density (210.46 tC/hm2). [Conclusion] The newly added afforestation in Youyu County has achieved remarkable carbon sequestration effects. In the future, the forest carbon sink capacity can be further enhanced through measures such as optimizing tree species structure and transforming shrub forests, and the value of carbon sink ecological products can be realized by relying on the national carbon market.