Abstract: Objective To study the pathogenic bacteria and their drug sensitivity in patients with advanced lung cancer accompanying lung infection. Methods Sputum culture and drug sensitivity test data about 56 patients with advanced lung cancer accompanying lung infection admitted to our hospital from March 2009 to May 2011 were retrospectively analyzed. Results Two hundred and twenty-eight strains were isolated from sputum.Of these strains,113(49.56%)were Gram-negative bacteria with Pseudomonas aeruginosa accounted for 18.86% followed by Bowman amobile bacteria,Klebsiella pneumoniae and E.coli,47(20.61%)were Gram-positive bacteria with coagulase negative staphylococcus accounted for 10.09% followed by Mycobacterium stercoris and Staphylococcus aureus,68(29.82%)were fungi with Candida albicans accounted for 14.04%.The Gram-negative bacteria were sensitive to ceftazidime,aminoglycoside and carbapenem.The Gram-positive bacteria were sensitive to vancomycin,teicoplanin and linezolid.Fungi were sensitive to fluconazole. Conclusion Gram-negative bacteria are the main pathogens in patients with advanced lung cancer accompanying lung infection.The key to its treatment is the rational use of antibiotics according to their drug sensitivity test.