Abstract PMs has adverse biological effects on major living organs in the body, including lungs. The complex composition of PM2.5, including carbon black and heavy metals, cause toxic effects to the lung. The synergistic effects of CB and Cd were less investigated in previous study. In our research, we deciphered the combination of CBs and Cd enhanced the cytotoxicity in BEAS-2B cells in vitro and in vivo. In the molecular level, the intracellular level of Cd increased, as a result of the cell membrane damage, causing high expression of MT-1 in BEAS-2B cells. Moreover, the expression of BAX increased, and the expression of BCL-2 decreased. Collectively, our data suggests the apoptosis effect of synergistic effects of CB and Cd exposure.