【Objective】This study aimed to elucidate the effects of different organic amendments (including corn straw, sheep manure, and biochar) application on the stability of soil aggregates and biological binding agents and to provide a scientific basis for carbon sequestration and fertilization improvement of red soil.【Method】The distribution of soil aggregates in different size and the contents of biological binding agents in aggregates were analyzed following six-year successive application of corn straw and sheep manure alone and in combination with biochar.【Result】Compared with the non-amended control, the contents of soil aggregates with particle size > 2 mm and 2-1 mm and the mean weight diameter (MWD) of soil aggregates were significantly increased by application of straw and sheep manure alone. In particular, the MWD and the aggregates of > 0.25 mm were significantly increased by 50% and 27.66% under straw amendment, while increased by 103.13% and 36.17% under sheep manure application alone, respectively. However, biochar alone or in combination with organic amendment did not affect the particle size distribution of soil aggregates. There were also no significant interactions between biochar and the organic amendment on the particle size distribution. The organic amendment had a significant effect on the soil organic carbon and microbial biomass carbon content of aggregates of each particle size. Also, the concentrations of soil organic carbon, microbial biomass carbon, total glomalin-related soil proteins (T-GRSP), and polysaccharides in macroaggregates (> 0.25 mm) were significantly increased by straw, sheep manure, and biochar application alone. Compared with the sole application of straw and sheep manure, biochar co-application significantly increased the soil organic carbon content in macroaggregates by 207% and 151%, the microbial biomass carbon by 78% and 62%, the T-GRSP by 15% and 20%, and the polysaccharide content by 24% and 22%, respectively. Biochar and organic amendment had a significant interactive effect on the soil organic carbon and microbial biomass carbon content in macroaggregates, silt, and clay particles. In addition, the combined application of biochar and organic amendment had a significant interactive effect on the content of polysaccharides. Random forest regression model analysis showed that the contents of easily extractable glomalin-related soil proteins (EE-GRSP), T-GRSP, and polysaccharides in aggregates were the key factors affecting the MWD.【Conclusion】These findings suggest that long-term successive application of straw and manure could significantly increase the stability of soil aggregates by increasing the microbial biomass carbon, total glomalin-related soil proteins, and polysaccharide in the macroaggregates. The combined application of biochar can promote the accumulation of biological binding agents in macroaggregates, which is more conducive to improving the structural stability and the potential of carbon sequestration and fertilization of red soil.