The ecological stoichiometric characteristics of soil aggregates present many interesting structural features linked to soil nutrient evaluation. However, the relationship between the ecological stoichiometry of soil aggregates and the soil nutrients is unclear. In this paper, we review the various aspects of ecological stoichiometric properties of soil aggregates, including those associated with the response of soil chemical parameters and soil structural features to environmental variations as well as the aspects related to the evolution of the forest age. Soil samples were selected among the soil profiles from Robinia pseudoacacia forests less than 20, 25, 40, and 50 years old in the Ansai County on the Loess Plateau (located in Shaanxi Province, China). By combining the soil chemical parameters in 0-20 cm and 20-40 cm soil layers, including soil organic carbon (C), total nitrogen (N), and total phosphorus (P), we aimed to determine the relationship of the ecological stoichiometric characteristics of soil aggregates and the soil nutrient content through stepwise multiple regression analysis. The results showed that the stoichiometric properties were limited by N content in soil aggregates from all stand ages of Robinia pseudoacacia forests. The C and N contents in soil aggregates and the C, N, and P stoichiometric ratios increased with increasing forest age. The C content ranged from 0.92 g/kg to 5.98 g/kg; the N content ranged from 0.15 g/kg to 0.48 g/kg; and the C/N, C/P, and N/P (C, N, and P stoichiometric ratios) ranged from 5.84 to 12.42, 1.91 to 12.00, and 0.33 to 0.97, respectively, in Robinia pseudoacacia forest stands of different ages. The C and N contents in soil aggregates and their C, N, P stoichiometric ratios in the 0-20 cm soil layer were higher than those in the 20-40 cm soil layer. However, the content of P did not vary significantly in both soil layers, ranging from 0.47 g/kg to 0.55 g/kg in soils from the forests with different age. The highest C, N, and P contents and corresponding stoichiometric ratios in soil aggregates of the two soil layers were found in aggregate particles with sizes ranging from 0.25 mm to 2 mm; the aggregates within this size range had a significant effect on soil C, N, and P contents and their stoichiometric ratios. In summary, the total nutrient contents in soil aggregates from Robinia pseudoacacia forest and their balance was significantly affected by the age of forest stands in the loess hilly regions, and it was mainly reflected in the aggregate particles that were 0.25-2 mm in size. Thus, Robinia pseudoacacia forest improved the capacity of soil nutrient conservation and supply by affecting the total nutrient contents of these aggregate particles and their balance.