Abstract: OBJECTIVE To observe the influence of transforming growth factor-β1 (TGF-β1 ) on Beas-2B apoptosis and cell cycle after Pseudomonas aeruginosa infection. METHODS The human lung epithelial cells Beas-2B were infected with P.aeruginosa.The expression levels of tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6) were detected by enzyme-linked immunosorbent assay before and after the Beas-2B cells were infected.The change of Beas-2B cell cycle was detected by flow cytometry before and after the infection, and the relative expression levels of TGF-β1 signaling pathway-related genes and proteins were detected by real-time fluorescent quantitative polymerase chain reaction (qRT-PCR) and Western blot (WB) before and after the Beas-2B were infected. RESULTS The expression levels of TNF-α and IL-6 in the cells were higher in the infection group than in the control group(P＜0.05).The apoptosis rate and S-phase ratio of the infection group were higher than those of the control group(P＜0.05).The expression levels of TGF-β1 and Smad2 genes and proteins of the infection group were higher than those of the control group; the expression levels of Smad7 gene and protein of the infection group were lower than those of the control group. CONCLUSION The P.aeruginosa infection may trigger the inflammatory response of the human lung epithelial cell Beas-2B, block the cell cycle in S phase and inhibit the cell division and proliferation, promote the cell apoptosis.