In order to investigate the influence of different cementing materials on the stability of macro-aggregate

this study investigated the content and types of organic and inorganic cementation material and macro-aggregate stability in the 0—100 cm soil profile of Quercus wutaishansea community in the Ziwuling forest region by field investigation and laboratory test

and analyzed the relationships between distribution of cementing material and its effect on macro-aggregate stability. The results showed: (1) Organic carbon and calcium carbonate showed completely opposite distribution in profile

and the content of organic carbon decreased with soil depth

the content of organic carbon in 0—20 cm soil layer was significantly higher than that in 20—100 cm soil layers. The content of calcium carbonate increased with soil depth

and the content in the 20—100 cm was significantly higher than 0—20 cm soil layers. (2) The aggregate stability was decreasing with the soil depth. The 20—70 cm layer had the most dramatic changes (compared with the 0—20 cm soil layers

the destruction rate increased by 581.00%). The proportion of aggregates destruction of 40—100 cm soil layer was 7.25 times larger than that of 0—20 cm soil layer

so the aggregate stability of surface was significantly higher than the bottom. While the clay content increased gradually with the increase of soil depth

but the change was not obvious. (3) The improvement of macro-aggregate stability mainly depended on the content of soil organic carbon. Mineral-associated organic carbon had the most direct effect on the stability of macro-aggregates in the organic carbon fractions. The results of this study revealed the distribution characteristics of main cementing materials and made clear that the mineral bound organic carbon was the most powerful cementing material which had a direct impact on the stability of the macro-aggregate of the loess. It provided a scientific basis for the cultivation of fine aggregate structure.