Although mesoporous carbon materials with hierarchical nanostructures have been produced by the synthesis of hybrid nanoparticles with a silicon dioxide (SiO2) core and a shell of resorcinol formaldehyde resin, it still remains a challenge to effectively tune the pore size distribution. Among a series of phenol derivatives, 3-aminophenol was found to exhibit not only excellent tunability of the size and low roughness of the sphere surface but also high pyrolysis yields in the synthesis of carbon nano/microspheres. Here, we report that mesoporous carbon networks with a bimodal pore size distribution in their hierarchical nanostructure were prepared by 3-aminophenol and formaldehyde polymerization on the SiO2 cores. In particular, the systematic control of the ratio of carbon precursors and silica nanoparticles provides a better control of the microstructure in hybrid nanoparticles with a shell of variable thickness composed of well-defined 3-aminophenol and formaldehyde resins, resulting in the tunability of their pore size distribution.