Iron-aluminum (hydro) oxides and phyllosilicates are two most important and active solid components in soil, accounting for over 90 percent in soil mass. Interactions between the two in the soil directly affect interface activity, physico-chemical properties, and fertility of the soil. Based on variation of some apparent characteristics displayed during the process of cementation of iron-aluminum (hydro) oxides with clay minerals in soil, effects of their interactions on physico-chemical properties of the soil were elucidated, and mechanisms of the interactions in both macro-and micro-scales discussed. It is proposed that more efforts be made to study interface characteristics and process of the transformation from non-crystal to crystal, in an attempt to further understanding of some soil basic problems, such as soil degradation, aggregate formation, element adsorption and desorption, control of soil pollutants, etc..