We report a new supramolecular method for the synthesis of well-defined pristine C-60/polymer colloid nanocomposites in water. The colloids include polymer micelles and emulsion particles. To a polymer colloid solution in water or alcohol, we introduced C-60 solution in a solvent that is miscible with water or alcohol. After the two solutions mixed., polymer colloids and C-60 spontaneously assembled into stable colloidal nanocomposites. After a dialysis process, a nanocomposite dispersion in pure water was obtained. As characterized by DLS and (Cryo-)TEM, the nanocomposites have a core-shell structure with C-60 aggregated on the surface of emulsion particles or micellar cores. The resulting nanocomposites have many potential applications such as biomedicals and photovoltaics.