Atmospheric nitrogen deposition can affect soil carbon and nitrogen dynamics by changing soil nitrogen availability (direct effect) and litter input (indirect effect). Soil aggregate is the most representative basic structural unit of forest topsoil, which is of great significance for the stable storage of organic carbon and nitrogen. The results showed that: (1) The contents of TOC (total organic carbon) and TN (total nitrogen) in layer A soil and aggregates with different particle sizes were significantly increased, and soil pH was significantly decreased by increasing (+L) and decreasing (-L) litter. Nitrogen addition significantly reduced the soil pH in layer B, which showed high nitrogen (HN) < low nitrogen (LN) < control (CK), and HN also significantly reduced the soil pH in layer A, and significantly increased the TOC content in layer B and aggregates. The addition of nitrogen and litter increase or decrease did not significantly affect the stability of soil aggregates. (2) Water stable macro aggregates (> 0.25 mm) was the dominant particle size in soil A and B, and the proportion of silt and clay (< 0.053 mm) was the lowest. The distribution of TOC and TN was the same in layer A and B. the contents of TOC and TN in > 2 mm aggregates were the highest, while those in 0.25 ~ 2 mm aggregates were the lowest. The contents of TOC and TN in layer A were higher than those in layer B. the contents of TOC and TN showed a V-shaped distribution with the decrease of soil aggregate size. (3) The stability of soil aggregates was positively correlated with the contents of TOC, TN, AN and AP, and negatively correlated with pH. The research results can provide reference for sustainable forest management.