【Objective】In soils iron oxides often congregate with lamellar phyllosilicates into various complex-like structures, thus generating significant impacts on physical and chemical properties of the soils. Phosphorus is an essential nutrient for growth of organisms in ecosystems, but may lead to eutrophication and deterioration of water quality, once it accumulates excessively in the soils. In soils phosphorus tends to be adsorbed onto minerals, and hence its mobility and bioavailability is significantly affected. Its adsorption by iron oxide-phyllosilicates associate differs from that by iron oxides and phyllosilicates separately in behavior. Yet, little has been done to explore effects of iron oxides-montmorillonite complex on speciation and bioavailability of phosphorus in soils. 【Method】In this paper, Montmorillonite-goethite complex (Mt-Goe) and complex of montmorillonite with amorphous or poorly crystalline iron oxides (Mt-HFO) were prepared, separately, and analyzed for structure, surface properties and features of adsorbing phosphate (Pi) and myo-inositol hexakisphosphate (IHP). 【Result】In Mt-Goe a small amount of hydroxyiron ions entered into the layers of montmorillonite, thus expanding the interlayer space, while montmorillonite was covered with goethite particles on the surface. In Mt-HFO, Fe³⁺ in-between the layers of monymorillonite hydrolyzed into hydroxy iron oxide and formed a layer of amorphous iron oxides on the surface of monymorillonite. The specific surface area of montmorillonite, Mt-Goe and Mt-HFO was 258.7, 185.4 and 226.4 m² ?g^-1 respectively, with surface fractal, isoelectric point and surface hydroxyl contents being on a rising order; and when pH was 5.5, the surface Zeta potential of the three was -46.1, -13.6 and -19.4 mV respectively. Pi and IHP adsorptions on the three types of samples were all dominated by homogeneous surface mono-layer adsorption. In terms of Langmuir saturated adsorption (q_max) and adsorption affinity, the three samples followed a decreasing order of Mt-HFO > Mt-Goe > montmorillonite. The pseudo-second-order kinetic model could be used to well fit Pi and IHP kinetic adsorption processes of the three samples, with adsorption rate constant following an order of Mt-HFO > Mt-Goe > montmorillonite. Compared to Pi, IHP was significantly lower in adsorption kinetic rate constant on the three samples, but significantly higher in q_max, and particularly low in adsorption rate on Mt-HFO, but much higher in q_max. 【Conclusion】Compared to montmorillonite, Mt-Goe and Mt-HFO are both lower in Pi and IHP adsorption rate, but higher in adsorption capacity. Among the two complexes, Mt-HFO is lower in Pi and IHP adsorption rate, but higher in adsorption capacity. All the three types of samples, montmorillonite, Mt-Goe and Mt-HFO, are lower in IHP adsorption rate than in Pi one, but much higher in IHP adsorption capacity than in Pi one.