Soil is the largest terrestrial organic carbon sink, and soil organic matter is the main form of the carbon stored in the sink. In view of the fact that soil organic matter plays an important role in the ecological system and carbon storage, the topic of soil minerals adsorbing organic matter and its mechanism is getting more and more attention from scientists the world over. This paper presents a review of the papers published in the past years about the mechanisms of soil minerals adsorbing organic matter and its major affecting factors. It is reported that among a huge number of soil minerals, hydrated iron, aluminum oxides and clay minerals are quite high in organic matter adsorbing capacity, ligand exchange, complexation, hydrogen bond, cationic bridge, condensation and Van der Waals force, the main mechanisms, and soil pH, the key factor that influences surface charge and adsorption sites of the mineral and hence adsorption of organic matter. Amount of the soil organic matter already adsorbed on the surface of the minerals also affects somewhat capacity of the minerals keeping on adsorbing organic matter, because the already adsorbed organic matter forms a layer covering part of the surface of the minerals and adsorbing sites thereon, and the closer the layer to the surface of the minerals, the tighter it adsorbed onto the minerals. Stability of the soil organic matter is affected significantly by the interaction between the organic matter and the minerals. Generally speaking, the adsorption of organic matter via chemical bond is the most stable and followed by that via Electronic “Donor-Acceptor” mechanism (which shows inner-sphere complex between functional groups on the surface of the minerals and the organic matter), and that via Van der Waals force and electrostatic force, in the end. In recent years, with the development of analytic equipment and technologies, some new characterizing and probing methods, such as TG, DSC, FTIR, SEM, TEM, AFM, STXM/NEXAFS, Neutron Scattering, have been invented and used in the studies on mechanisms of mineral-organic matter associations (MOAs). These instrument developments will undoubtedly bring important new insights into mechanisms of MOAs. However, relatively little has been reported about effects of microorganisms on mineral adsorption of organic matter, formation and evolution of MOA, though it is quite obvious that their effects are crucial.