The development of hollow carbon balls by CO2 oxidation of two types of carbon blacks was studied. Super P (SP) and Denka Black (DB) were used for this study. Specificsurface area (SSA), structural parameters, and microstructures were examined using Brunauer, Emmett and Teller apparatus, X-ray diffraction spectroscopy, and transmission electron microscope (TEM), respectively. The SSAs of both oxidized carbon blacks increased after oxidation. The SSAs of raw DB and SP were 73 m2/g and 60 m2/g, respectively. Maximum SSAs of oxidized DB and SP were 152 m2/g and 253 m2/g, respectively. The d002 of DB and SP showed almost no change after oxidation. The Lc of raw DB (38Å) and SP (19Å) increased with increasing weight loss. The Lc of SP increased up to 254 at 96% weight loss. The SSA increased about twice in DB (148 m2/g) and about four times in SP (254 m2/g) after 3 h oxidation compared with the original carbon blacks. Through TEM observation the outer parts of the oxidized carbon blacks showed a rigid shell structure and the inner parts looked empty. Generally it looked like an angular soccer ball, so we named it ‘hollow carbon ball.’ It is expected that the hollow carbon ball can be used as catalyst supports.