Vegetation succession affects soil physical and chemical properties, including organic carbon functional group species, quantities, and structural changes. Changes in soil organic carbon (SOC) functional groups during the vegetation restoration process could reveal the processes governing changes in the composition and properties of humus. The study was on the Loess Plateau in the Ziwuling forest region of Shaanxi Province, where various stages of secondary forests have developed. At different phases of development, vegetation systems in this region have changed from pioneer herbage species, which initially colonized abandoned croplands, (Bothriochloa isehemum, Artenmisia giradii, Stipa bungeana, Artenmisia sacrorum, Spodiopogen sibiricus, Sophora flavecens, Themeda japonica, and Arundinella anomala), to secondary shrubs (Hippophae rhamnoides, Sophora viciifdia, and Ostryopsis davidiana), to an early forest community (Populus davidiana, Betula platyphylla, and Platycladus orientalis with groups of trees and/or shrubs), and finally to a Liaotungesis community forming the mature forest. The SOC content in the 0-40 cm soil layer increases significantly during the vegetation succession from abandoned cropland to mature Liaotungesis forest. The rate of increase in SOC is different during vegetation succession, and organic carbon functional groups varied among the different plant communities. Recent studies using synchrotron-based C(1s) near-edge X-ray absorption fine structure (NEXAFS) have shown it to be an effective, non-invasive technique, which can be used to identify and fingerprint the complex structural characteristics of SOC. Consequently it can be used to investigate the impact of management on the composition and biogeochemical cycling of organic C at the molecular level in terrestrial ecosystems. This synchrotron radiation technology has rarely been used to study SOC structure in China before so we used it in this study with the objective of developing a new method to explore the effect of the succession process under typical plant species (Bothriochlor ischaemum, Sophora viciifolia, Quercus liaotungensis) on changes in SOC functional groups. The time succession sequence could be inferred from current vegetation spatial arrangements. Therefore, we collected samples from two soil layers (0-5 cm,20-40 cm) in soil profiles under selected vegetation systems typically representing different vegetation succession stages in the region. Results obtained, which were qualitatively analyzed, indicated that aliphatic-C and ketone-C absorption intensities in samples from the 0-5 cm and 20-40 cm soil layers increased significantly during the vegetation process: the peak intensity of aliphatic-C of the 0-5cm layer was greater than in the 20-40 cm layer; the ketone-C absorption intensity of samples from the 0-5 cm soil layer was less than in the 20-40 cm layer. Results of a semi-quantitative analysis showed that the functional groups' relative percentage content in the 0-5 cm soil layers increased during the plant succession process, and the aliphatic-C aromatic-C, and ketone-C contents followed a gradually increasing trend. For the Quercus liaotungensis community, the aliphatic-C relative percentage content increased significantly in the 20-40 cm soil layer. The results show that the SOC functional groups from different land use-type samples were basically identical, and that the revegetation affected the change in the quantity of SOC functional groups during the revegetation process. Revegetation can promote increases in aliphatic-C and ketone-C contents in both the 0-5 cm and 20-40 cm soil layers, and this effect gradually increased with prolonged revegetation time This illustrated that the vegetation succession enhanced SOC chemical stability.