The content of soil complexing in paddy soils developed from purple soils appears in the sequence of neutral soils > calcareous soils > acid soils and decreases with depth of soil layer, while the degree of organo-mineral complexing is in the order of calcareous soils > neutral and acid soils and increases with the depth of soil layer. The content and degree of <0.01mm soil particle aggregation are in the sequence of calcareous soil > neutral soils > acid soils. The content of soil complexing is positively related with the contents of organic matter, physical clay, Fe oxide and <0.01mm soil particle aggregation. But the degree of organo-mineral complexing is negatively related to content of organic matter, but insigificantly related to the combined forms of humus, the content of physical clay and the degree of <0.01mm soil particle aggregation. The complexing humus with mineral (content of soil complexing) in soil organic matter plays an important role.in soil particle aggregation. The content of <0.01mm soil particle aggregation depends on the content of soil complexing to a great extent. The relationship between complexing of organo-mineral and aggregation of soil particle is reflected by the relationship between the content of soil complexing and the content of <0.01 mm soil particle aggregation.