As one of the common manganese oxides easily generated and widely distributed in the supergene environment, manganite participates in the formation of Fe(Ⅲ) oxides, affecting the migration, transformation and fate of Fe²⁺ in aqueous systems. In this study, the redox mechanism was studied by determining the intermediates, and the influence of initial pH and air(oxygen) on the processes was studied in simulated aqueous systems with pH value in the range of 3-0~7.0. The influence of Fe²⁺ concentration, pH value, and air(oxygen) on ferric(hydr) oxide crystal strucutres, chemical compositions and the redox rate was studied in closed and open aqueous systems. The results indicate that goethite and lepidocrocite are formed as the major products of Fe²⁺ oxidation by manganite. Goethite and lepidocrocite tend to be formed when pH values are controlled at 3.0~5.0 and 7.0, respectively. High concentration of Fe²⁺ facilitates the formation of lepidocrocite. The introduction of air(oxygen) is convenient for the generation of goethite of high crystallinity. The redox rate of manganite and Fe²⁺ increases with the increase of pH value and oxygen partial pressure in reaction systems. The present study facilitates the understanding of the natural genesis of ferric oxides on the surface of manganese oxides.