ObjectiveTo investigate the occurrence and  epidemiological characteristics of healthcareassociated infection (HAI) in patients with extracorporeal circulation operations.MethodsClinical data of 731 patients with extracorporeal circulation operations in a hospital from September 2010 to December 2011 were studied retrospectively.ResultsOf 731 patients ,  87 developed 103 episodes of HAI, HAI rate and episode rate was  11.90% and 14.09% respectively . HAI  rate in patients with  congenital heart disease, rheumatic heart disease and other cardiovascular disease was 9.74%, 10.69%, and 31.82% respectively（χ2=27.54，P＜0.05) .  The most common infection site was lower respiratory tract (72.82%), followed by blood stream  (14.56%), urinary system (7.77%), pleural cavity (1.94%), gastrointestinal tract (1.94%), and  surgical sites (0.97%).   The pathogenic examination rate was 35.57%（260/731） ,  112 pathogenic strains were isolated , 89 (79.46%) of which were gramnegative bacteria ,18 (16.07%) were  grampositive bacteria  and 5 (4.46%) were fungi .There were 28 isolates of  multidrugresistant Acinetobacter baumannii, 3 methicillinresistant Staphylococcus aureus and 7 methicillinresistant coagulase negative Staphylococcus, all Klebsiella pneumonia and Escherichia coli isolates were βlactamaseproducing strains.ConclusionHAI rate in patients with  extracorporeal circulation operations are high, drug resistance of pathogen is high, monitor should  be intensified to reduce the occurrence  of HAI.