Iron oxide-kaolinite association is an important component of the soils in South China and a critical factor influencing physical and chemical properties of these soils. Hence, formation and transformation processes of crystalline iron oxide-kaolinite association and their influencing factors were studied with Fe (II) as catalyst. Results show that Fe(II) accelerated association of crystalline iron oxide with kaolinite, which offset the inhibiting action of kaolinite to some extent on the formation of crystalline iron oxides When the molar ratio ( R ) of Fe (II) to Fe (III) was in the range of 0.04～0.06, Fe(II) accelerated association of kaolinite with lepidocrocite, goethite and hematite, and when R ≥0.1, magnetite-kaolinite association readily formed. In addition, Fe(II) accelerated association of kaolinite with lepidocrocite and goethite at pH 5～6 and 50～60℃, with hematite at 80℃ and neutral pH, and with magnetite at pH 9. Kaolinite reduced the catalytic effect of Fe(II) on formation of crystalline iron oxides and influenced type and morphology of the iron oxides formed. These findings may serve as valuable reference for the study on formation and transformation of iron oxides and iron oxides-kaolinite associations in natural environments.