OBJECTIVE: To investigate the distribution and the antibiotic susceptibility of pathogenic bacteria in children from Guiyang with lower respiratory infection (LRI). METHODS: The nasopharyngeal aspirate samples were obtained from 893 hospitalized children with LRI between August 2006 and June 2008. An antibiotic susceptibility test was performed using the VITEK system and the Kirby-Bauer diffuse method after bacteria were identified. RESULTS: Five hundred and forty-three patients (60.8%) were bacteria-positive. A total of 598 strains (30 kinds of bacteria) were obtained from the sputum samples. Of them, 533 strains (89.1%) were gram-negative and 57 were gram-positive (9.8%). Escherichia coli (E. coli) and Kleb-siella pneumoniae (K. pneumoniae) were common in gram-negative strains. They were susceptive to piperacillin/tazobactam, amikacin, ciprofloxacin, and levofloxacin, especially to imipenem. Streptococcus pneumoniae (S. pneumoniae) and Stapthylococcus aureus (S. aureus) were common in gram-positive strains. S. pneumoniae was susceptive to penicillin and cefazolin sodium, but S. aureus was resistant. Both were high susceptive to vancomycin, and resistant to roxithromycin. CONCLUSIONS: Gram-negative bacteria are the main pathogens in children from Guiyang with LRI, and E. coli and K. pneumoniae are common. The antibiotic susceptibility of pathogenic bacteria varies with different strains of bacteria. A reasonable selection of antibiotics should be based on the antibiotic susceptibility test.［Chin J Contemp Pediatr, 2009, 11 (12):964-966］