Ecological restoration is vital to improve soil structure and promote the accumulation of soil organic carbon(SOC). The effects of ecological restoration on SOC and its labile fractions, aggregate-associated organic carbon have been widely studied,but the relation of SOC fractions(especially POC and MOC) and aggregate in natural restoration measures(secondary forests) and the planted restoration measures(Chinese prickly ash planting) are still unclear. To analyze the accumulation characteristics and mechanisms of SOC under ecological restoration based on the influence of soil carbon fractions on aggregates and aggregate-associated organic carbon, we chose ecological restoration measures(secondary forest, 15-20 a; Chinese prickly ash planting,15-20 a) and control cropland(>50 a) in a typical dry-heat valley rocky desertification region as the study subjects. The contents were measured in soil layers(0-10 cm and 10-20 cm), including soil organic carbon(SOC), particulate organic carbon(POC), easily oxidizable organic carbon(EOC), mineral associated organic carbon(MOC), non-liable organic carbon(NLOC), aggregates and aggregate-associated organic carbon. We studied the effect of ecological restoration on SOC and its fractions, aggregates and aggregate-associated organic carbon. The results shows that:① Compared with the cropland, ecological restoration significantly increased the content and storage of SOC and its fractions(except MOC) in the 0-20 cm soil layer, with increments ranging from 10.4% to 151.7% and 6.3% to 134.5%, respectively. The content and storage of POC and EOC increased largely in the SOC fractions, which showed the stronger relationship with SOC. ② Ecological restoration significantly increased>2 mm aggregates content, mean weight diameter(MWD) and mean geometric diameter(MGD), which increased greatly with 379.3%, 172.0% and 265.2% among the 0-10 cm soil layer of the secondary forest. ③ Ecological restoration significantly increased the aggregate-associated organic carbon content of various particle sizes. The degree of improvements in aggregate-associated organic carbon content decreased with aggregates size increasing. However, after ecological restoration, carbon contribution in >2 mm aggregates increased significantly and carbon contribution in<2 mm aggregates decreased significantly. Carbon contribution in soil aggregates shifted to the chief contribution in>2 mm aggregates. The increase of>2 mm aggregates content was the main causes for carbon contribution in>2 mm aggregates increasing. ④ More than 2 mm aggregates content, MWD, MGD, and carbon contribution in>2 mm aggregates were positively correlated with SOC, POC, EOC and NLOC(P<0.05). And they had stronger correlation for POC and EOC(P<0.01). In addition, from SOC and its fractions, the number and stability of aggregates, and carbon contribution in>2 mm aggregates, natural restoration measures increased greater than the planted restoration measures. The study suggests that SOC fractions(especially POC and EOC), aggregates and aggregate-associated organic carbon became more abundant in secondary forest and Chinese prickly ash planting than in cropland, which highlighted that ecological restoration plays a crucial role in soil carbon sequestration in rocky desertification region.