Abstract: Carbon foam composites were prepared by a self-foaming method from mesophase pitch using mesocarbon microbeads (MCMBs), PAN based carbon fibers (PAN-CFs) and ZrO₂ nanoparticles were used as the fillers for reinforcement. The effects of the fillers on the foaming behavior and the compressive strength were investigated. Results show that ZrO₂ nanoparticles produce a larger increase in the compressive strength of the carbon foam than do MCMBs and PAN-CFs. The compressive strength of the carbon foam increases from 7.57 to 31.4 MPa when 30% of the ZrO₂ nanoparticles is added to the mesophase pitch. The foam formation obeys the hot-point nucleation mechanism, in which gaseous products released from light hydrocarbons are heated to generate nuclei by localized condensation reaction heat.