The distribution of organic carbon in different size soil aggregates was studied in hilly-gully region on the Loess Plateau,and also the relationship among soil aggregates,organic carbon and vegetation restoration was analyzed. The results showed that:(1) The organic carbon content in the 0~20 cm soil layer was higher than that in the 20~40 cm layer under different vegetation covering.The organic carbon content in different plant communities were Stipa grandis P.smirn community > Stipa bungeana Trin.community> Artemisia sacrorum Ledeb.community > Thymus mongolicus Ronn.community;(2) There were obvious relations between the organic carbon content and the soil aggregates size,the higher of soil carbon content were in 0.5~0.25 mm and the 1~0.5 mm two size in soil aggregates,organic carbon content decreased along with the soil aggregates size increases;(3) The revegetaion years also had a certain influence to the organic carbon content in different size soil aggregates.The organic carbon content assumed the trend of escalation along with the increasing of revegetation years returning back from agricultural land to grassland.The vegetation worked on the soil organic carbon quality and quantity by the withered leaves and other matters,meanwhile they ameliorate soil structure,especially the contents of water stable aggregates.The accumulation of soil organic was affected by vegetation types,revegetation years and also aggregates sizes in loess hilly-gully region.