Objective： To investigate the influence of moxibustion products on mitochondrial transmembrane potential （MTP） and mRNA expression of Bax/Bcl-2 in alveolar type Ⅱ epithelial A549 cells, and to further explore influence of moxibustion products on the oxidative damage of A549 cells. Methods： Smoke and particles generated by moxibustion were collected using the filter box for gas sampling. The moxa smoke extract （MSE） was diluted sequentially to the final concentrations of 0.05 mg/mL, 0.2 mg/mL, 0.2 mg/mL, 0.3 mg/mL and 0.4 mg/mL using the cell culture medium, and A549 cells were then intervened by the above MSE solution. Cell MTP was detected by JC-1 staining. Fluorescence quantitative polymerase chain reaction （PCR） was used to detect Bax/Bcl-2 mRNA expression of A549 cells. Results： Compared with cells in the normal control group, MTP was significantly decreased in cells of 0.3 mg/mL and 0.4 mg/mL MSE intervention groups （P〈0.01）; while MTP showed no significant changes in cells of 0.05 mg/mL, 0.1 mg/mL and 0.2 mg/mL MSE intervention groups （P〉0.05）; compared with cells in 0.05 mg/mL MSE intervention group, MTP was decreased significantly in cells of 0.1 mg/mL, 0.2 mg/mL, 0.3 mg/mL and 0.4 mg/mL MSE intervention groups （P〈0.05）; compared with cells in 0.1 mg/mL MSE intervention group, MTP was decreased significantly in cells of 0.4 mg/mL MSE intervention group （P〈0.01）. Bax mRNA expression of cells in each concentration of MSE intervention group all showed no significant difference compared to that in the normal control group; Bcl-2 mRNA expression of cells was reduced with the increase of MSE intervention concentration. Wherein, Bcl-2 mRNA expressions of cells in 0.4 mg/mL and 0.3 mg/mL MSE intervention groups were significantly reduced compared with that of cells in the normal control group （P〈0.05）; Bcl-2 mRNA expression of cells in 0.4 mg/mL MSE intervention group was significantly reduced compared to that in 0.05 mg/mL MSE intervention group （P〈0.05）. C
