Mesoporous mania spheres with a high monodispersity were synthesized by employing monodisperse poly(styrene-co-methacrylic acid) (PSMAA) particles as templates The mania nanoparticles coated on the PSMAA spheres were first re-dispersed in the mixed solvent and subsequently infiltrated into the swollen PSMAA spheres After calcinations to remove completely PSMAA, monodisperse mesoporous mania spheres were obtained, displaying an average particle size of about 130 nm and a pore size distribution centered around 4 nm