“Dry water” has aroused wide interest in recent years, especially in the emerging field such as micro- and nano-reactor, because of its special liquid-in-solid-in-air property; however, the application “dry water” as micro- and nano-reactor and polymerization has not been studied yet. In this work, dry liquid has been prepared through a high-shear mixing of hydrophobic fumed silica particles (H18) and monomer (e.g. maleic acid) in a conventional blender; then polymerization is carried out via initiating the monomer under a proper reaction condition; ultimately, a kind of organic-inorganic nanocomposite coated with a layer of self-assembled hydrophobic silica nanoparticles are formed. Subsequently, the difference between the polymerization of dry liquid and conventional ways has been preliminary studied in terms of reaction conditions, reaction rate, molecular weight and its distribution, etc.; revealing that dry water has some potential applications on preparing organic-inorganic nanocomposites.