Objective To investigate the influence of application of local anesthesia with lidocaine on bronchial lavage fluid (BLF) pseudomonas aeruginosa culture and drug sensitivity in cases with lung infection .Methods Two hundred and seventy speci-men of BLF were collected from 135 patients with infection of lung .And BLF were collected directly from right-broncho in control group ,and from left-broncho in lidocaine group .The outcome of pseudomonas aeruginosa culture and drug sensitivity were com-pared in the two groups .Results Fourty-two cases were postitive in BLF pseudomonas aeruginosa culture in the control group ,and 40 cases were postitive in lidocaine group .The positive rates were 31 .11% and 29 .63% ,respectively .There were no significance between the two groups (P<0 .001) .Compared with the control group ,the sensitive strains of pseudomonas aeruginosa were obvi-ously less and the drug tolerance strains were much more in lidocaine group for Ciprofloxacin and Levofloxacin (P<0 .05) .Howev-er ,there were no influence for drugs such as Piperacillin/Tazobactam and Ceftazidime ,etc .Conclusion 2% lidocaine has no influ-ence on the outcome of BLF pseudomonas aeruginosa culture .But it may reduce the drug sensitivity of Ciprofloxacin and Levofloxa-cin in cases with infection of lung .