Abstract: 【Objectives】 Study on the distribution of soil organic carbon and nitrogen in different sizes of water-stable aggregates as affected by long-term various fertilization modes, will deepen the understanding of the soil carbon sequestration and nitrogen fixation.【Methods】Based on a long-term fertilization experiment in Eum-Orthic Anthrosols in Yangling City, Shaanxi Province, soil samples of 0-10 cm and 10-20 cm horizons were collected from the 9 different fertilization treatmentsCK, N, NP, NK, PK, NPK, straw returning + NPK (SNPK), suitable manure + NPK (M1NPK), high manure input + NPK (M2NPK). Soil organic carbon and total nitrogen contents in water-stable aggregates of 2 mm, 2-1 mm, 1-0.5 mm,0.5-0.25 mm and 0.25 mm were analyzed. 【Results】 The SOC and TN contents in 0-10 cm soil lager are 20% significantly higher than in 10-20 cm soil layer. The highest SOC and TN contents are in the aggregates of 2-1 mm and /or 1-0.5 mm sizes, the lowest in aggregates of 0.25 mm size. The SOC and TN contents in N, NK and PK treatments are similar to those in CK. The NP, NPK and SNPK treatments significantly increase the SOC and TN contents in the two soil layers compared to CK. In 0-10 cm soil layer of above corresponding treatments, the SOC contents increased by 16%-43%, 9%-40% and 22%-47%, and the TN contents by 28%-48%, 39%-61% and 39%-91%, respectively. In 10-20 cm soil layer, the SOC contents are increased by 35%-49%, 17%-40% and 45%-46%, and the TN contents by 44%-47%, 39%-54% and 54%-64%, respectively. The long term application of manure plus NPK treatments (M1NPK and M2NPK) cause significant increase of SOC and TN contents in all size of aggregates. The increments of SOC in 0 -10 cm are from 68% to 122% and from 61% to 163%,and those of TN contents are from 84% to 133% and from 97% to 175%, respectively, and in 10-20 cm layer the increments of SOC are from 20% to 61% and from 39% to 118% and the TN contents are from 43% to 86% and from 107% to 136%, respectively. More than 40% of SOC and TN contents are distributed in aggregates 0.25 mm size fraction, less than 10% in 2-1 mm size. The treatments of NP and NPK with or without organic amendments show significant lower proportions of SOC and TN in large aggregates ( 2 mm or 2-1 mm), and higher proportions in small aggregates (1-0.25 mm) in 0-20 cm layers. The C/N ratios show no consistent trend in aggregates. However, C/N ratios in aggregates in the fertilizer treatments are lower than that in CK after the long term fertilization. 【Conclusions】 The combined application of NP or NPK fertilizers without or with organic amendments significantly increase SOC in all aggregates in 0-10 cm soil layer. The MNPK treatment significantly increases SOC partitioning in 1-0.25 mm of aggregates, and consequently not only increases SOC storage but also conserves high TN in the soil.