Objective To study the pathogenic bacteria distribution and drug resistance characteristics in HIV/AIDS patients with lower respiratory tract infection in Yunnan province,so as to guide the clinical medication. Methods We collected 278 cases of hospitalized patients with sputum,alveolar lavage specimen smear,culture, positive specimens from HIV/AIDS patients with lower respiratory infection in The Third People's Hospital of Kunming from January 2008 to December 2012.Then we retrospectively analyzed the collected data.Results From 278 cases of sputum and alveolar lavage fluid specimens,we isolated a total of 127 strains of bacteria (45.7%),53 strains of fungus (19.1%),50 strains of white candida,3 strains of aspergillus,49 strains of mycobacterium,44 strains of mycobacterium tuberculosis,and the rest of atypical mycobacteria.Gram negative bacilli accounted for 64.6%,followed by pneumonia klebsiella bacteria,pseudomonas aeruginosa,e.coli,acinetobacter,sewer,e. coli,gram-positive bacteria accounted for 15.4%.Fungi accounted for 19.1%,and candida albicans was the common fungus.Mycobacterium tuberculosis accounted for 17.6%.Gram-negative bacilli were sensitive to imipenem, ptilinum ketone/sulbactam and amikacin,gram-positive bacilli were sensitive to vancomycin,nitrofurantoin and imipenem.Conclusions The major pathogenic bacteria are gram-negative bacilli in HIV/AIDS patients with lower respiratory tract infection in Yunnan province,but fungal infection ratio is increasing year by year,and conditional pathogenic bacteria are the major pathogen,which have antimicrobial resistance with different degree,TB infection rate is high and multi-drug resistant TB appears.Antimicrobial agents should be rationally used to delay the appearance of pathogen resistance.