Revegetation is a traditional practice widely used for soil protection. We evaluated the effect of natural revegetation succession on soil chemical properties and carbon fractions(particulate organic carbon(POC), humus carbon(HS-C), humic acid carbon(HA-C) and fulvic acid carbon(FA-C)) on the Loess Plateau of China. The vegetation types, in order from the shortest to the longest enclosure duration, were:(a) abandoned overgrazed grassland(Ab G3; 3 years);(b) Hierochloe odorata Beauv.(Hi O7; 7 years);(c) Thymus mongolicus Ronnm(Th M15; 15 years);(d) Artemisia sacrorum Ledeb(At S25; 25 years);(e) Stipa bungeana Trin Ledeb(St B36; 36 years) and(f) Stipa grandis P. Smirn(St G56; 56 years). The results showed that the concentrations of soil organic carbon, total nitrogen and available phosphorus increased with the increase of restoration time except for Th M15. The concentration of NH4-N increased in the medium stage(for Th M15 and At S25) and decreased in the later stage(for St B36 and St G56) of vegetation restoration. However, NO3-N concentration significantly increased in the later stage(for St B36 and St G56). Carbon fractions had a similar increasing trend during natural vegetation restoration. The concentrations of POC, HS-C, FA-C and HA-C accounted for 24.5%–49.1%, 10.6%–15.2%, 5.8%–9.1% and 4.6%–6.1% of total carbon, respectively. For Ab G3, the relative changes of POC, HS-C and FA-C were significantly higher than that of total carbon during the process of revegetation restoration. The higher relative increases in POC, HS-C and FA-C confirmed that soil carbon induced by vegetation restoration was sequestrated by higher physical and chemical protection. The increases of soil C fractions could also result in higher ecological function in semiarid grassland ecosystems. Revegetation is a traditional practice widely used for soil protection. We evaluated the effect of natural revegetation succession on soil chemical properties and carbon fractions (particulate organic carbon (POC), humus carbon (HS-C), humic acid carbon (HA-C) (FA-C)) on the Loess Plateau of China. The vegetation types, in order from the shortest to the longest enclosure duration, were: (a) abandoned overgrazed grassland (Ab G3; 3 years); (b ); Hierochloe odorata Beauv. (Hi O7; 7 years); (c) Thymus mongolicus Ronnm (Th M15; 15 years); (d) Artemisia sacrorum Ledeb B36; 36 years) and (f) Stipa grandis P. Smirn (St G56; 56 years). The results showed that the concentrations of soil organic carbon, total nitrogen and available phosphorus increased with the increase of restoration time except for Th M15. The concentration of NH4-N increased in the medium stage (for Th M15 and At S25) and decreased in the later stage (for St B36 and St G 56 concentrations of POC, HS-C, FA-56) of vegetation restoration. However, NO3-N concentration significantly increased in the later stage (for St B36 and St G56). Carbon fractions had a similar similar trend trend during natural vegetation restoration. C and HA-C for 24.5% -49.1%, 10.6% -15.2%, 5.8% -9.1% and 4.6% -6.1% of total carbon, respectively. For Ab G3, the relative changes of POC, HS-C and The higher relative increases in POC, HS-C and FA-C confirmed that soil carbon induced by vegetation restoration was sequestrated by higher physical and chemical protection. The increases of soil C fractions could also result in higher ecological function in semiarid grassland ecosystems.