Calcium carbonate (CaCO3) in the presence of single-walled carbon nanotube (SWCNT) /fullerodendron supramolecular nanocomposites was crystallized with a CO2 diffusion method under ambient conditions and in aqueous environments to produce monodisperse spherical SWCNT/CaCO3 hybrids with a core-shell structure. The crystals nucleate at the carboxyl groups on the surface of the SWCNT/fullerodendron supramolecular nanocomposites grow around a spherical scaffold consisting of the SWCNTs, and finally form spherical calcite crystals embedded with and covered by the SWCNTs. Owing to of the phase transition from vaterite to calcite through a solvent-mediated process, the morphology of the microspheres is unique; the shell is primarily composed of calcite crystals of CaCO3, and a greater amount of SWCNTs is embedded in the core moiety. Polymer Journal (2012) 44, 620-624; doi:10.1038/pj.2012.36; published online 18 April 2012