ObjectiveTo realize the characteristics of communityonset multidrug resistant organism infections (MDROCOIs).MethodsA prospective investigation was conducted on patients with positive culture of Staphylococcus aureus, Enterococcus,Escherichia coli,Klebsiella pneumoniae, and Acinetobacter baumannii between July 1， 2008 and June 30，2010.Results A total of 1 646 episodes of Staphylococcus aureus, Enterococcus, Acinetobacter baumannii, Escherichia coli, and Klebsiella pneumoniae infections occurred, 1 148 of which were COIs, including 470 (40.94%) MDRO infections ; 498 of which were hospitalonset （HO） infections ，including 260 (52.21%) MDRO infections, which was significantly higher than that of MDROCOI rate (χ2＝17.87, P=0.00). MDROCOI pathogens were mainly from sputum or bronchial secretion (171/470, 36.38%),the next was urine(166/470, 35.32%), these samples accounted for 71.70% of all. Of all departments, MDROCOI rate was the highest in intensive care unit(ICU) (64.75%). For the infection sites of COIs, respiratory MDRO infection was the highest (60.71%).ConclusionMDROCOIs are serious, the management of patients with MDROCOIs should be enhanced, transmission in the hospital should be avoided.