OBJECTIVE： To investigate the distribution and drug resistance of Pseudomonas aeruginosa in nosocomial infections to provide the scientific evidence for the clinical use of the antibiotics. METHODS： 124 strains of P. aeruginosa were isolated from sputum， hydrothorax， urine， wound secretion， blood and so on submitted by outpatient and inpatient department of our hospital during Apr. 2013-Apr. 2014. Isolated P. aeruginosa were cultured and identified according to National Rules of Clinical Laboratory Procedures （2nd edition）， and drug resistance was analyzed by K-B method. RESULTS： A total of 124 strains of P. aeruginosa mainly isolated from ICU （23 strains， 18.55％）， respiratory medicine department （17 strains， 13.71％） and brain surgery department （14 strains， 11.29％）. Sites of infection were sputum， wound secretion. Resistance rate of P. aeruginosa to cefotaxime， cefepime and aztreonam were over 50％. CONCLUSIONS： Drug resistance of P. aeruginosa is very serious. During drug therapy， it is necessary to monitor antibiotics sensitivity regularly， and use antibiotics alternatively for different patients in different wards， in order to prevent the generation and spread of drug-resistant strain as far as possible， and improve or consolidate therapeutic efficacy.