To investigate the impact of long-term combined application of organic and inorganic fertilizers on soil aggregate stability and organic carbon content，a 14-year field experiment was conducted with four treatments:no fertilizer(CK)，chemical fertilizer only(CF)，chemical fertilizer plus farmyard manure(OF)，and chemical fertilizer plus bio-organic fertilizer(BF). The study examined the effects of different fertilization practices on soil aggregate stability and organic carbon content. The results showed that:① Fertilization(CF & OF & BF)increased the proportion of >2，1-2，and <0.053 mm size fractions，and the combined organic-inorganic fertilization(OF & BF)further enhanced the proportion of larger aggregates(>0.25 mm)，promoted the transformation of micro-aggregates into macro-aggregates.②Combined organic-inorganic fertilization(OF & BF)improved the structure of soil aggregates，stability indexes of water-stable macro-aggregates such as large aggregate content(>0.25 mm)and stability indicators such as mean weight diameter and geometric mean diameter，with the best performance observed in the bio-organic fertilizer(BF)treatment. ③ Among all treatments，the contribution rate of organic carbon from macro-aggregates(>0.25 mm)exceeded 62.0%，with the combined organic-inorganic fertilization showing a contribution rate of over 65.9%. Macro-aggregates were the primary storage size class for organic carbon，with 0.5-1 and 0.053-0.25 mm being important size ranges affecting soil organic carbon. ④ Long-term combined organic-inorganic fertilization(OF and BF)increased the total soil organic carbon content，with bio-organic fertilizer being more beneficial for enhancing soil organic carbon levels.⑤ Compared to no fertilizer(CK)，the variability in the contribution rate of organic carbon from farmyard manure(OF)and bio-organic fertilizer(BF)decreased by 43.6% and 45.7%，respectively. The distribution of organic carbon in each particle size fraction of the soil was more coordinted，and the stability of aggregate was enhanced. The above results indicated that combined organic-inorganic fertilization was beneficial to the transformation of micro-aggregates into macro-aggregates，increased the proportion of soil macro-aggregates，and balanced the contribution of organic carbon nutrients among different aggregate size classes. The effect was more pronounced with the addition of bio-organic fertilizer，which could provide a basis for long-term fertilization management.