In order to investigate the composition and stability of soil aggregates and explore the soil structure of Chinese fir plantation, in this study, 0—100 cm soil layers of Chinese fir plantation in different developmental stages were taken as the object, dry sieving was used to determine composition of soil aggregates and wet sieving was used to determine the stability of aggregates. The results showed that under the dry sieve treatment, the soil aggregates of the Chinese fir plantations were dominated by macroaggregates (＞0.25 mm) at each developmental stage, which was above 80%, and the proportion of soil macroaggregates in middle age forest and mature forest was higher than that of young forest in each soil layer, it had significant difference in 0—20 cm soil layers; In each soil layer, for the soil aggregates with clay diameter ＞5 mm, which had a higher proportion and had a significant effect on the composition of soil aggregates with the different developmental stages of Chinese fir. Under the wet sieve treatment, the proportion of water stable macromolecule (＞0.25 mm) was significantly decreased with the increase of soil layer in each developmental stage, for the 0—80 cm soil layers, the proportion of water stable macromolecule of middle age and mature forest was higher than young forest, for the 0—20 cm and 20—40 cm soil layer, the proportion of water stable macromolecule of middle age forest were 41.79% and 39.06% higher than that of the young forest, which had significant difference; The PAD characteristics of soil aggregates displayed an opposite trend as compare to water stable macromolecules in each developmental stage of Chinese fir plantation, MWD and GMD decreased significantly with the increase of soil layer, and the GMD of soil aggregate in middle age forest and mature forest were significantly higher than those of young forest in 0—100 cm soil layers. Therefore, the stability of soil aggregates in Chinese fir plantation decreased with the increase of soil layer, and the soil structure of middle age forest and mature forest was better than that of young forest.