Abstract： Objective To investigate the distribution and antibiotic susceptibilities of quantitatively cultivated bacteria from bronchoalveolar lavage fluid (BALF) samples. Methods Totally 312 BALF samples were streak inoculated to chocolate,blood and MAC plates with 10 μL annulus,and the bacterial colony ＞ 104 CFU/mL was considered pathogenic bacteria. The identification of pathogenic bacteria was carried out with Vitek 2-Compact,and Kirby-Bauer disc agar diffusion method,Etest and dilution method were used for antibiotics sensitivity test.Results Totally 216 (69.2％) strains of pathogenic bacteria were isolated.The major gram-negative strains were Pseudomonas aeruginosa,Acinetobacter baumannii,Klebsiella pneumoniae and Escherichia coli, and the major gram-positive strains were Staphylococcus aureus,Streptococcus pneumoniae and Staphylococcus epidermidis.The resistance rate of Pseudomonas aeruginosa to aztreonam was high,but lower than 30％ to piperacillin/tazobactam,imipenem,cefepime,ofloxacin,ceftazidime and amikacin.Staphylococcus aureus was highly resistant to erythromycin,benzylpenicillin and clindamycin,but it was sensitive to furadantin,vancomycin,quinupristin/dalfoprisdn,tigecycline and linezolid.Conclusion The positive rate of BALF cultivation is high,and the main pathogenic bacteria Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Staphylococcus aureus and Escherichia coli are resistant to several commonly used antibiotics.