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This paper focuses on environmental risk caused by livestock manure disorderly discharged from integrated livestock and poultry industry. 2-year pot experiment was carried out to study the effects of pig manure organic fertilizer on fluvo-aquic soil organic carbon, available nutrient content and soil aggregate distribution, which designed in 5 levels of organic fertilizer application(0, 6.7, 13.3, 26.7, 40.0 g.kg-1 soil). The results showed that the organic carbon, alkali-hydrolyzable nitrogen, available P and available K contents in soil were enhanced with organic fertilizer application increasing, and the indicators of soil were increased significantly in second year, such as organic carbon content was 2.7%~54.0% higher than that of the first year, alkali-hydrolyzable nitrogen content was higher 6.7%~34.6%, available P content was higher 36.8%~ 159.5% and available K content was higher 20.3%~35.7%. There was a significant linear relationship between soil organic carbon content and external organic carbon input. Organic fertilizer application could significantly improve lettuce yield, and it had a significant effect. The soil micro-aggregate contents for 0.053~0.25 mm and <0.053 mm took a larger percentage of total soil aggregates, and showed a decreasing trend with organic fertilizer application increasing, while the contents of 0.25 ~0.5 mm and >0.5 mm soil macro-aggregates were increased with organic fertilizer application increasing. Organic fertilizer application could promote soil macro-aggregates formation, when the pig manure organic fertilizer applied 40.0 g.kg-1 soil, the contents of >0.25 mm soil aggregates reached maximum, and also the mean weight diameter(MJFZ)) and geometric average diameter( GWD) of soil aggregates were higher than that of other treatments, the soil agglomeration became more stronger and the soil structure became more stable. [ABSTRACT FROM AUTHOR]