Abstract: 【Objective】As an important soil physical attribute, soil aggregates are the major site for soil organic carbon sequestration, so the impacts of long-term fertilization on aggregates characteristics and organic carbon distribution in a reddish paddy soil were studied in Dongting Lake Plain, China, which can provide a theoretical evidence for fertilization management in double cropping rice area. 【Method】Undisturbed soil samples at 0-20 cm layer were collected from a 27 years (1986-2013) field experiment, which was established in the Hanshou county in Hunan province. The experiment included 4 treatments: CK (without fertilization), NPK (N, P, K fertilizer application), LOM (combined application of NPK and 30% organic manure fertilizers), HOM(combined application of NPK and 60% organic manure fertilizers). All soils were separated into five aggregate-size classes (＞5 mm, 2-5 mm, 0.5-5 mm, 0.25-0.5 mm and ＜0.25 mm) by wet sieving method and the macro aggregates fractions (＞0.25 mm) were chosen for results analysis. The amount, mean weight diameter, geometric mean diameter, fractal dimension of water-stable aggregates which denoted by WR_0.25, MWD, GMD and D were exampled, separately. The aggregate-associated organic carbon was also measured.【Result】In addition to the size group of ＞5 mm, along with decreasing of particle sizes, the proportion of water-stable aggregates and the contribution rate of aggregates fractions to soil organic carbon (SOC) in the treatments increased, while the water-stable aggregate-associated organic carbon presented an opposite trend. Both the proportion of aggregates in the 2-5 mm and 0.5-2 mm size fractions were significantly increased under fertilization treatments when compared to CK treatment and the increasing rate was up to 35.5%-64.5% and 6.2%-14.7%, respectively. Fertilizer application also increased the value of WR_0.25, MWD, and GMD of aggregates by 8.6%-12.5%, 7.1%-15.1%, and 13.7%-28.4%, respectively. As for the fractal dimension, its value of fertilization treatments decreased by 2.3%-3.5% than that of CK, which suggesting that long-term addition of chemical N, P, K fertilizers or organic manure was beneficial to the improvement of soil structure. Long-term fertilization significantly increased the contents of organic carbon in various sizes of aggregates and the effect was much more obvious when combined application of organic manure and chemical N, P, K fertilizers, the content of aggregate-associate organic carbon of HOM treatment reached the highest, with the amplification up to 22.1%-36.6% when compared to CK. It also showed that 69.9%-83.5% of the SOC was concentrated in the macro water-stable aggregates and the percentage among different treatments decreased in the order of HOM＞LOM＞NPK＞CK. As for the contribution rates of aggregates to bulk SOC, there was a significant increase when the aggregates with size fractions ＞0.5 mm under fertilization treatments, while the allocation rates of SOC in the aggregates with size fractions of 2-5 mm and 0.5-2 mm were more sensitive to fertilization application. The results of correlation analysis revealed that there exists a significant positive correlation between the percentages of soil water-stable aggregates with the size of ＞0.5 mm and the content of SOC, indicating that newly enriched SOC mostly appeared in the size group of ＞0.5 mm. 【Conclusion】After long-term chemical N, P, K fertilizers or organic manure application, the contents of macro water-stable aggregates and organic carbon in reddish paddy soil increased obviously. Compared with single chemical N, P, K fertilizers application, chemical manure mixed with 60% organic manure application showed more obvious effects on the improvement of soil structure and the enhancement of soil carbon sequestration and was considered as the best fertilization mode for the tested paddy soil.