This paper investigated the antibacterial mechanism of the Cu-antibacterial White Carbon Black containing cerium. The sol-gel method was used to prepare the White Carbon Black carrier. Cu2+ was selected to be the antibacterial ion, and cerous nitrate was selected to be the additive. They were synthesized on the white carbon black carrier. The structure and antibacterial mechanism of antibacterial material were characterized by inductively coupled plasma, Fourier transform infrared spectroscopy and enumeration tests (Escherichia coli as experimental bacterium). Results showed that the contents of antibacterial ions in the Cu-antibacterial white carbon black containing cerium were higher than those for the general Cu-antibacterial white carbon black (without containing cerium). Cu2+ was bound to white carbon black by ion exchange process. Bacteriostasis rate is over 99%. Furthermore, other advantages of this material are its good thermal and light stabilities.