Abstract: Objective　To analyze the pathogenic bacterium distribution of elderly patients with nosocomial infection and drug resistance，and provide the reference for reasonable clinical use of antibacterial drugs.  Methods　In Huangpu District 3 secondary general hospitals from January 2009 to December 2010，the specimens were collected from elderly patients with nosocomial infection，and determined for the analysis of pathogenic bacterium identification and drug resistance.  Results　In 369 cases of elderly patients with nosocomial infection， a total of 179 strains of pathogenic bacterium were detected， including 120 gram-negative bacteria （67.0%），38 gram-positive bacteria （21.2%） and 21 fungi （11.8%）. The drug resistant rates of Escherichia coli and Acinetobacter baumannii to carbapenems were 11.1% and 14.2% respectively. The resistance of gram-positive bacteria to penicillins and third generation cephalosporin increased gradually.  Conclusions　Pathogens of elderly patients with nosocomial infection are opportunistic，mainly as gram-negative bacilli. The resistance is high， and the proportion of fungal infection rapidly rises. Therefore，etiological examination and medicine sensitive monitoring should be paid attention，and they will contribute to the clinical rational selection and use of antibacterial drugs.

Key words: Elderly patient, Nosocomial infection, Drug resistant rate