ObjectiveTo investigate the prevalence rate of healthcareassociated infection(HAI) in a hospital, so as to provide reference for making HAI control measures. MethodsThe crosssectional survey on HAI was carried out among all hospitalized patients on May 26, 2010, December 12, 2012 and December 4, 2013, respectively, surveyed data were analyzed. ResultsThe prevalence rate was 6.66%(n=116）, 6.67%（n=113） and 6.33%（n=120）in 2010,2012 and 2013 respectively, and case rate was  7.29%（n=127）,7.38%（n=125）and 6.97%（n=132） respectively,  intensive care unit( ICU ) had the highest infection rate, internal medicine ICU was up to 71.43%. The main infection site was lower respiratory tract（44.53%）,  followed by surgical site infection (9.11%) and urinary tract infection (9.11%). The isolation rate of gramnegative bacteria,  grampositive bacteria and fungi was 60.81%, 20.38% and 18.81% respectively. Usage rate of antimicrobial agents in three years was 32.95%,29.87% and 25.59% respectively （χ2=13.16，P＜0.01）.ConclusionPrevalence rate of HAI in this hospital is high , the main pathogen is gramnegative bacteria, the main infection site is  lower respiratory tract , antimicrobial use  decreased year by year. Monitor on high risk departments, main sites and pathogens should be intensified.